In-text — Infographics, Activity Strips and Data Stories — Tales by Dots and Lines

1. 15 marksGanita Prakash Cl-8 Part 2, Section 5.2, page 124 — 'Infographics'

   The 'Wheat vs Rice' infographic maps the difference between per capita rice and wheat consumption to a value from −100 (mostly wheat) to +100 (mostly rice) for each state. (i) Karnataka's value is hidden — what could it be? (ii) Which are the top 5 rice states? (iii) The top 5 wheat states? (iv) Which states are more or less balanced?

   Hint. Every state carries a printed number except Karnataka; for Karnataka, compare its shade against the colour scale and against its neighbours.

   How to read the infographic. Each state is shaded on a scale running from deep orange at −100 ('mostly wheat') through pale cream at 0 ('prefer both') to deep purple at +100 ('mostly rice'). A value of +100 does not mean a state eats no wheat — it means rice leads wheat by the largest margin found. The red line drawn across the map marks the geographical split, and the national figure is +13.48, 'Rice Wins'.

   (i) Karnataka's hidden value. Its shade is a mid-purple, clearly on the rice side. Comparing it against the colour bar and against its neighbours settles the range: it is lighter than Kerala (+79), Tamil Nadu (+85) and Undivided Andhra (+92), and darker than Goa (+57). Matching its exact shade against the scale places it at roughly +65 to +70.

   That is a sensible answer on food grounds too — Karnataka eats a great deal of rice, but northern Karnataka is jowar-and-wheat country, which pulls the state figure below its coastal and southern neighbours.

   (ii) Top 5 rice states. Sorting the printed values downwards: Manipur +100, Nagaland +99, Mizoram +97, Tripura +96, Meghalaya +95 (Arunachal +93, Undivided Andhra +92 and Assam +91 follow closely.) The entire top of the list is the North-East.

   (iii) Top 5 wheat states. Sorting the printed values upwards (most negative first): Rajasthan −93, Haryana −81, Punjab −78, Madhya Pradesh −60, Delhi −45 (Gujarat −37 and Uttar Pradesh −30 come next.) These are all in the north-west.

   (iv) States that are more or less balanced. Balanced means a value close to 0: · Bihar +3 — by far the most balanced state on the map · Maharashtra −15, Uttarakhand −18, Himachal Pradesh −19 — mildly wheat-leaning but close to even · Uttar Pradesh −30 and Gujarat −37 are leaning to wheat but nowhere near the extremes

   What the map says overall. There is a clean north-west versus south-and-east split, marked by the red line: wheat dominates the north-western plains and rice dominates the south, the east and the North-East, with a narrow band of balanced states running along the divide. The pattern tracks climate and cropping — rice needs plentiful water and is grown in high-rainfall and delta regions, while wheat suits the drier winters of the north-western plains.

   ✦ (i) Karnataka is about +65 to +70 — a mid-purple, lighter than Kerala's +79 and darker than Goa's +57. (ii) Rice: Manipur (+100), Nagaland (+99), Mizoram (+97), Tripura (+96), Meghalaya (+95). (iii) Wheat: Rajasthan (−93), Haryana (−81), Punjab (−78), Madhya Pradesh (−60), Delhi (−45). (iv) Balanced: Bihar (+3) above all, then Maharashtra (−15), Uttarakhand (−18) and Himachal Pradesh (−19).

2. 26 marksGanita Prakash Cl-8 Part 2, Section 5.2, pages 125-126 — 'What can a Strip Say?'

   Manoj records his day on a strip of 48 boxes, each box being 30 minutes from midnight to midnight, using one colour per activity. Three strips are shown for three days. (i) What activity does each colour stand for? (ii) The strips are Friday to Sunday in some order — which is which? (iii) On one day he went to a long movie with friends; when? (iv) When does his school break for lunch? (v) What more can the strips tell us?

   Hint. Find the colour that fills the small hours first, then the one that always follows it, then the long midday block.

   Reading the strips box by box. Measuring each of the 48 boxes on all three strips gives:

   Strip 1 — blue 00:00–06:30, purple 06:30–08:00, yellow 08:00–09:00, green 09:00–09:30, orange 09:30–12:30, green 12:30–13:00, grey 13:00–13:30, orange 13:30–16:30, grey 16:30–17:00, blue 17:00–17:30, yellow 17:30–18:30, green 18:30–19:00, orange 19:00–20:30, blue 20:30–24:00.

   Strip 2 — blue 00:00–07:00, purple 07:00–08:00, green 08:00–08:30, grey 08:30–09:00, yellow 09:00–12:30, green 12:30–13:00, orange 13:00–13:30, yellow 13:30–16:30, grey 16:30–17:00, orange 17:00–18:30, green 18:30–19:00, yellow 19:00–19:30, orange 19:30–20:30, blue 20:30–24:00.

   Strip 3 — blue 00:00–07:00, purple 07:00–08:00, green 08:00–08:30, grey 08:30–09:00, yellow 09:00–12:30, orange 12:30–13:00, grey 13:00–13:30, green 13:30–14:00, blue 14:00–15:00, orange 15:00–18:30, grey 18:30–19:00, green 19:00–19:30, yellow 19:30–20:00, orange 20:00–21:30, blue 21:30–24:00.

   (i) What each colour means. · Blue = sleeping — it fills the small hours on every strip and returns at night. · Purple = showering, dressing, yoga or exercise — it always comes immediately after the long blue block, i.e. first thing after waking. · Green = eating — it appears in three short half-hour slots per day, at breakfast, lunch and dinner times. · Grey = travelling — always a single half-hour box sitting immediately before or after a school block. · Yellow = attending classes, studying and homework — it forms the long 09:00–16:30 blocks on two of the strips. · Orange = meeting friends, hobbies, media and time with family — it dominates the strip with no school block.

   (A small slip in the book: the text says five types of activity but then lists six, and the strips do use six colours.)

   (ii) Which day is which. · Strip 2 = Friday. A full school day: travel out at 08:30, classes 09:00–12:30, lunch break, classes again 13:30–16:30, travel home at 16:30, and homework in the evening. · Strip 3 = Saturday. School runs only 09:00–12:30, then travel home at 13:00, a late lunch, an afternoon nap and a free afternoon and evening — a half-day at school. · Strip 1 = Sunday. No school block at all: a later wake-up (06:30, and a longer 1½ hours of exercise), a long free morning, then out from 13:00 to 17:00.

   (iii) The long movie. On Strip 1 (Sunday) he travels at 13:00–13:30, spends 13:30–16:30 — a solid three hours — in the orange 'meeting friends' activity, then travels back at 16:30–17:00. A single unbroken three-hour block away from home with friends is exactly what a long movie plus the trip looks like, so it happened on Sunday afternoon, roughly 13:30 to 16:30.

   (iv) The school lunch break. On Strip 2 (Friday) the yellow school block is interrupted by green (eating) at 12:30–13:00 and orange (free time) at 13:00–13:30, with classes resuming at 13:30. On Strip 3 (Saturday) school also stops at 12:30. So school breaks for lunch at 12:30, with the break running an hour until 13:30.

   (v) What else the strips reveal. Counting the boxes for each colour gives the day's budget:

   	Sleep	Eat	Wash/exercise	Study	Free time	Travel
   Friday	10.5 h	1.5 h	1 h	7 h	3 h	1 h
   Saturday	10.5 h	1.5 h	1 h	4 h	5.5 h	1.5 h
   Sunday	10.5 h	1.5 h	1.5 h	2 h	7.5 h	1 h

   The striking find is that Manoj sleeps exactly 10.5 hours on all three days and eats for exactly 1.5 hours on all three — but the split between studying and free time swings from 7 h / 3 h on Friday to 2 h / 7.5 h on Sunday. He keeps his sleep constant by shifting his bedtime and by adding naps: on Sunday he wakes at 06:30 and takes a half-hour nap at 17:00, and on Saturday he goes to bed at 21:30 but naps a full hour after lunch. Each row also adds to exactly 24 hours, which is a good check that no box has been misread.

   ✦ (i) Blue = sleeping, purple = washing/exercise, green = eating, grey = travelling, yellow = school and study, orange = friends, hobbies and family. (ii) Strip 2 = Friday (full school day), Strip 3 = Saturday (half day), Strip 1 = Sunday (no school). (iii) The long movie was on Sunday, about 13:30 to 16:30. (iv) School breaks for lunch at 12:30, resuming at 13:30. (v) He sleeps exactly 10.5 hours and eats exactly 1.5 hours every one of the three days; what changes is study time (7 h → 4 h → 2 h) traded against free time (3 h → 5.5 h → 7.5 h).

3. 33 marksGanita Prakash Cl-8 Part 2, Section 5.2, pages 126-127 — 'Data Story: Sleepy-Deepy'

   A line graph shows typical sleep duration of Indians across ages 6 to 75. Share your observations, and explain why a line graph is a better choice here than a column graph.

   Hint. Count how many data points there are, and ask what 70 columns would look like.

   What the graph shows. · At age 6 the average sleep time is about 9.5 hours a day. · Sleep time falls steadily through the teenage years and into adulthood. · It reaches a low of about 8 hours a day between ages 30 and 50. · After 50 it climbs again, reaching about 8.5 hours by age 75.

   So the curve is roughly U-shaped — long sleep in childhood, a long shallow trough through the working years, and a gentle recovery in later life. The total range is only about 1.5 hours across a lifetime of 70 years, which is why the chapter prints a zoomed-in version alongside: on a scale starting at 0 the whole curve would look almost flat.

   Why a line graph and not columns. The graph contains 80 data points placed very close together, which is why it looks like a smooth curve rather than a chain of straight segments. Drawing the same data as a column graph would need about 70 columns side by side — cluttered, heavy and almost impossible to read a trend from. The line is light, and the shape is the whole message here: what matters is not any single age's value but the fall, the flat stretch and the rise.

   A caution about the numbers. These are averages across many people. Individual sleep needs vary a great deal with age, living conditions, diet, activity and much else, so a 40-year-old sleeping 7 hours is not defying the graph. The chapter notes that adults typically need 7 to 9 hours and that babies sleep far longer than the youngest age shown here.

   Questions worth asking next. Why do newborns and infants sleep so much? Do people in other countries follow the same curve? Do animals show a similar pattern of sleep changing with age?

   ✦ Average sleep falls from about 9.5 hours at age 6 to about 8 hours between ages 30 and 50, then rises to about 8.5 hours by 75 — a shallow U-shape. A line graph suits the data because there are 80 closely spaced points; the same data as roughly 70 columns would be cluttered and would hide the very trend the graph exists to show.

Solutions written by the tuition.in editorial team and checked against NCERT Ganita Prakash Grade 8 Part 2 (hegp205.pdf), Chapter 5 'Tales by Dots and Lines', pages 103-133. HAND-WRITTEN throughout. Part 2 books carry NO printed answer key, so every numeric answer was derived from first principles and independently recomputed in Python. MEASURED OFF THE PRINTED FIGURES at 300-1200 dpi: the page-113 dot plot reads 4, 7, 8, 8, 9, 9, 9, 9, 9, 11 (ten dots, so the missing eleventh is 16); the three page-114 album dot plots read A = 5, 5, 5.25, 5.5, 5.75, 6, 6.5 (mean 39/7 = 5.5714), B = 0.5, 0.75, 1.5, 1.5, 2, 3.75, 4.25, 5 (mean 2.406) and C = 3.5, 3.5, 3.5, 4, 4, 4, 4.25, 4.5 (mean 3.906), so A is the 5.57 album; the page-115 cycle dot plot reads 0:3, 1:1, 2:4, 3:7, 4:7, 5:5, 6:4, 7:6, 8:3, 9:0, 10:2 (N = 42, sum 193, mean 4.595, median 4 — and the book's own hint that four students rode twice confirms the reading); the page-128 dot plot reads 14:2, 15:2, 16:3, 17:5, 18:4, 19:4, 20:3, 21:1, 22:0, 23:1 (N = 25, sum 443, mean 17.72); the page-122 New Delhi rainfall line reads 1.3, 1.5, 1.5, 1.1, 1.5, 3.8, 9.7, 9.7, 4.0, 1.0, 0.4, 1.0 days, total about 37, which makes New Delhi the least-rainy of the four cities and Port Blair the most at 125.8; the page-123 births line graph was found to span April 2017 to March 2020 (36 monthly points) with July 2017 about 1.77 M, January 1.67/1.75/1.77 M in 2018/19/20 and a 2019 total of about 21.4 M; the page-124 Wheat-vs-Rice infographic was read state by state and Karnataka's hidden shade was matched against the colour bar (calibrated exactly on Kerala +79 and Chhattisgarh +80) to about +68; the page-125 activity strips were decoded box by box across all 48 boxes of all three strips, giving Friday/Saturday/Sunday and an identical 10.5 hours of sleep and 1.5 hours of eating on each day; the page-130 hobbies line graph gives urban age 10 about 2 h 06 min and rural 1.5 h at age about 14.3, so option (d); the page-132 sunrise/sunset charts give Kibithu the earliest January sunrise (05:57, day length 10 h 31 min) and Srinagar the longest day of the year (14 h 25 min in June); and the page-132 moon chart gives purnima about the 14th and amavasya about the 28th-29th with a measured daily lag of 49 minutes. TWO SLIPS IN THE PRINTED BOOK ARE FLAGGED: page 125 says Manoj recorded 'five types of activities' and then lists six (the strips do use six colours), and the page-122 Figure it Out numbers two different questions as '2'.. Questions are referenced from the NCERT textbook for identification.