90% of what number is 45?

0.9x = 45

Solve for x

To find out what number is 90% of another number, you can use the concept of finding a percentage. Here's how you can calculate it:

Step 1: Convert the percentage to a decimal by dividing it by 100. In this case, 90 divided by 100 is 0.9.

Step 2: Set up an equation representing the relationship between the unknown number and the given percentage. Let's call the unknown number "x". The equation would be: 0.9 * x = 45.

Step 3: Solve the equation for "x" by dividing both sides of the equation by 0.9: x = 45 / 0.9.

Calculating this expression, we get a result of x = 50.

Therefore, 90% of 50 is 45.