Question

I thought of a number 400. i reduces it by a few percent and got 220. by what percent did i reduce the number

a) 40%
b) 45%
c) 55%
d) 60%

Answer 1

To determine the percentage by which the number was reduced, you can use the formula for percentage decrease. In this case, the percentage decrease is 45%. The correct answer is b) 45%.

Step-by-step explanation:

To find the percentage by which you reduced the number, you can calculate the percentage decrease using the formula:

Percentage decrease = ((Initial value - Final value) / Initial value) * 100

In this case, the initial value is 400 and the final value is 220.

Thus, the percentage decrease = ((400 - 220) / 400) * 100 = (180 / 400) * 100 = 0.45 * 100 = 45%.

Therefore, you reduced the number by 45%, so the correct answer is b) 45%.

Answer 2

The number 400 was reduced by 45% to get 220. This was calculated by finding the difference (180) and then determining what percentage that difference is of the original number (400).

Step-by-step explanation:

To find by what percent the student reduced the number 400 to get 220, we need to calculate the difference between the two numbers and then find out what percentage that difference is of the original number (400).

First, let's find the difference:

• 400 - 220 = 180

Now, let's calculate what percent 180 is of 400:

• (180 / 400) x 100 = 45%

Therefore, the student reduced the number 400 by 45%.