Question

Mark the correct alternative in each of the following:

If x = (−10) + (−10) + ... 15 times and y = (−2) × (−2) × (−2) × (−2) × (−2), then x − y =

(a) 118 (b) −118 (c) −182 (d) 182

Answer 1

x = (−10) + (−10) + ... 15 times

= − (10 + 10 + ... 15 times)

= −150

y = (−2) × (−2) × (−2) × (−2) × (−2)

= −(2 × 2 × 2 × 2 × 2) (When the number of negative integers in a product is odd, the product is negative)

= −32

∴ x − y = −150 − (−32) = −150 + 32 = −118

Hence, the correct answer is option (b).