Question

Last month the cost of using the air pump at a garage was 20p.

Answer 1

Answer:

Tom is incorrect

The cost of using the air pump has increased by 150%

Step-by-step explanation:

Tom is incorrect

percent change = [ (difference between initial and final value) ÷ initial value] × 100

⇒ [ (50 - 20) ÷ 20) × 100 = 150%

Therefore, the cost of using the air pump has increased by 150%