### All PSAT Math Resources

## Example Questions

### Example Question #1 : How To Find Percentage Equivalent To A Decimal

If 20% of x is equal to 160% of y, then y is what percent of x?

**Possible Answers:**

12.5

1.25

125

800

8

**Correct answer:**

12.5

We are told that 20% of x is equal to 160% of y. We need to write expressions for 20% of x and 160% of y and set them equal to one another.

In order to find an expression for 20% of x, we can write 20% as a decimal and multiply it by x. Since 20% = 0.20, we can write 20% of x as 0.2x.

Similarly, we can write 160% as 1.60y.

Now, we set these expressions equal to one another.

0.2x = 1.60y.

Since the question asks us to find y as a percentage of x, we need to solve for y in terms of x. Let's divide both sides of the equation by 1.60.

0.125x = y.

Therfore, y is equal to 0.125x, which is the same as 12.5% of x, since 12.5% expressed as a decimal is 0.125.

The answer is 12.5.

### Example Question #1 : Decimals And Percentage

Express .789 as a percentage.

**Possible Answers:**

789%

0.789%

78.9%

7.89%

**Correct answer:**

78.9%

Move the decimal two places to the left to convert a decimal to a percentage. Therefore, .789 is equivalent to 78.9%.

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