Question

2. Find the percentage change from the first quantity to the second quantity:

(i) $75; $90
(ii) 40 cm; 60 cm
(iii) 20 gm; 5 gm

Answer 1

a) 20%

b) 50%

c) -75%

Explanation:

Mathematically, percentage change is;

(new value -old value)/old value * 100%

(i) (90-75)/75 * 100%

= 15/75 * 100% = 20%

ii) (60-40)/40 * 100%

= 20/40 * 100% = 50%

iii) (5-20)/20 * 100% = -15/20 * 100% = -75%