15 ÷ 40 × 100

= (15 × 100) ÷ 40

= 1500 ÷ 40

= 37.5

**Now we have: 15 is what percent of 40 = 37.5%**

If you want to learn more, then please keep reading, and you won't be disappointed.

We already have our first value **15** and the second value **40**. Let's assume the unknown value is **Y** which answer we will find out.

As we have all the required values we need, Now we can put them in a simple mathematical formula as below:

STEP 1Y = 1540

By multiplying both numerator and denominator by 100 we will get:

STEP 2Y = 1540 × 100100 = 37.5100

STEP 3Y = 37.5

Finally, we have found the value of Y which is 37.5 and that is our answer.

If you want to use a calculator to find **15 is what percent of 40**, simply enter **15 ÷ 40 × 100** and you will get your answer which is **37.5**

Here is a calculator to solve percentage calculations such as 15 is what percent of 40. You can solve this type of calculation with your values by entering them into the calculator's fields, and click *'Calculate'* to get the result and explanation.

**Question:** You have found your aunt’s freshly baked cookies vault which, she just baked! She told you not to eat more than 15 cookies from those, and you ended up eating 40 of them! What percent of the cookies have you eaten?

**Answer:** 37.5 percent of the cookies that she baked.

**How To:** The key words in this problem are "What Percent" because they let us know that it's the Percent that is missing. So the two numbers that it gives us must be the "Total" and the "Part" we have.

PartTotal = Percent

In this case, it's the Total of those cookies that your aunt's baked. So we put 15 on top and 40 on the bottom of the fraction, and now we're ready to figure out the part we don't know; the Percent.

1540 = Percent

To find the percent, all we need to do is convert the fraction into its percent form by multiplying both top and bottom part by 100 and here is the way to figure out what the Percent is:

1540 × 100100 = 37.5100

37.5 = Percent

And that means you ended up eating 37.5 Percent of the cookies that she baked.

**Step 1:** Let's solve the equation for Y by first rewriting it as: **100% / 40 = Y% / 15**

**Step 2:** Drop the percentage marks to simplify your calculations: **100 / 40 = Y / 15**

**Step 3:** Multiply both sides by 15 to isolate Y on the right side of the equation: **15 ( 100 / 40 ) = Y**

**Step 4:** Computing the left side, we get: **37.5 = Y**

This leaves us with our final answer: **15 is 37.5 percent of 40**