Mathematical Operations — Practice

Question 1

If A means +, B means −, C means ×, D means ÷, then 8 C 2 A 4 B 6 = ?
(a) 12 (b) 14 (c) 16 (d) 18

Accepted Answer

(b) 14.

8 × 2 + 4 − 6 = 16 + 4 − 6 = 14.

Question 2

If '×' means '−', '−' means '÷', '÷' means '+', '+' means '×', then 6 × 4 ÷ 2 = ?
(a) 2 (b) 4 (c) 6 (d) 8

Accepted Answer

(b) 4.

Substitute: 6 − 4 + 2 = 4.

Question 3

If '+' means '−', '−' means '×', '×' means '÷', '÷' means '+', then 15 − 3 + 10 × 5 ÷ 5 = ?
(a) 42 (b) 45 (c) 48 (d) 50

Accepted Answer

(c) 48.

Substitute: 15 × 3 − 10 ÷ 5 + 5 = 45 − 2 + 5 = 48.

Question 4

If '+' means '−', '−' means '×', '×' means '÷', '÷' means '+', then 18 × 6 ÷ 3 − 2 + 4 = ?
(a) 3 (b) 5 (c) 7 (d) 9

Accepted Answer

(b) 5.

Substitute: 18 ÷ 6 + 3 × 2 − 4 = 3 + 6 − 4 = 5.

Question 5

If '>' means +, '<' means −, '=' means ×, then 5 > 2 = 3 < 4 = ? (a) 5 (b) 6 (c) 7 (d) 9

Accepted Answer

(c) 7.

5 + 2 × 3 − 4 = 5 + 6 − 4 = 7 (multiply first).

Question 6

Which two signs, interchanged, make the equation 5 + 3 − 2 = 4 correct?
(a) + and − (b) + and × (c) − and ÷ (d) × and ÷

Accepted Answer

(a) + and −.

Swapping gives 5 − 3 + 2 = 4, which is true. As written it equals 6.

Question 7

Which combination of signs makes 6 _ 3 _ 2 _ 4 = 8 correct?
(a) ÷ × + (b) × ÷ − (c) + − × (d) − + ÷

Accepted Answer

(a) ÷ × +.

6 ÷ 3 × 2 + 4 = 2 × 2 + 4 = 8.

Question 8

If P = ÷, Q = ×, R = +, S = −, then 18 Q 12 P 4 R 5 S 6 = ?
(a) 51 (b) 52 (c) 53 (d) 54

Accepted Answer

(c) 53.

18 × 12 ÷ 4 + 5 − 6. Left to right for ×/÷: 18 × 12 = 216, ÷ 4 = 54; then 54 + 5 − 6 = 53.

Question 9

If '−' and '÷' are interchanged and '+' and '×' are interchanged, then 20 − 4 ÷ 5 + 2 × 10 = ?
(a) 5 (b) 10 (c) 15 (d) 25

Accepted Answer

(a) 5.

Substitute: 20 ÷ 4 − 5 × 2 + 10 = 5 − 10 + 10 = 5.

Practice — Mathematical Operations