Question

A tailor had a piece of cloth. He initially reduced its length by 80%. After this, he further shortened it by 90% of its new length. What was the percentage decrease in the cloth's length from the first to the second cut?

• A. 50%
• B. 80%
• C. 30%
• D. 40%

Answer 1

The Correct Option is A

Let's assume the initial length of the cloth is 100 units.

After the first cut, the length becomes: 100 - (80% of 100) = 100 - 80 = 20 units.

After the second cut, the length becomes: 20 - (90% of 20) = 20 - 18 = 2 units.

The decrease from the point after the first cut (20 units) to the point after the second cut (2 units) is 20 - 2 = 18 units.

To find the percentage decrease, we divide the decrease by the original value after the first cut and multiply by 100:

Percentage decrease =\(\left( \frac{18}{20} \right) \times 100 = 90\%\)

Since the value after the first cut is 20 units and it decreased to 2 units, which is half of 20 units, the percentage decrease is 50%.