Question

Today, Reza ate 20 grapes, which was 400% as many grapes as he ate yesterday. Explain how to use equivalent ratios to find the number of grapes Reza ate yesterday.

Answer 1

To use equivalent ratios to find the number of grapes Reza ate yesterday, we need to set up a ratio comparing the number of grapes he ate today to the number of grapes he ate yesterday.

Let's start by assigning a variable to represent the number of grapes Reza ate yesterday. Let's call it "x".

According to the problem, Reza ate 20 grapes today, which is 400% as many grapes as he ate yesterday.

To find the number of grapes Reza ate yesterday, we can set up the following ratio:

20 grapes today / x grapes yesterday = 400% / 100%

Since 400% is equal to 4, 400% / 100% simplifies to 4/1.

So, the equivalent ratio is:

20 / x = 4 / 1

Now we can cross-multiply and solve for x:

20 * 1 = x * 4

20 = 4x

Dividing both sides of the equation by 4:

20 / 4 = 4x / 4

5 = x

Therefore, Reza ate 5 grapes yesterday.