Correct Answer:
B. 25%
The correct answer is 25%. Percentage increase is calculated by finding the absolute increase (new value minus original value), dividing it by the original value, and then multiplying by 100.
Step-by-Step Solution
- Identify Original and New Lengths:
Original length = 72 cm
New length = 90 cm - Calculate the Absolute Increase:
Increase = New length - Original length
Increase = 90 - 72 = 18 cm - Compute the Percentage Increase:
Percentage Increase = (Increase ÷ Original length) × 100
= (18 ÷ 72) × 100
= 0.25 × 100
= 25% - Verification:
25% of 72 cm = (25/100) × 72 = 18 cm.
72 cm + 18 cm = 90 cm, which matches the new length exactly.
Thus, the increasing percentage is 25%.