Question

The ratio of red jellybeans to yellow jellybeans is 3:4. Jerry eats 3 red jellybeans and 6 yellow leaving the remaining ratio of red jellybeans to yellow jellybeans as 4:5. How many yellow jellybeans were originally in the jar?

Answer 1

Let's start by using algebra to solve the problem.

Let's call the original number of red jellybeans "3x" (since the ratio of red to yellow is 3:4, we can think of the total number of jellybeans as 3x + 4x = 7x, where 4x is the number of yellow jellybeans).

After Jerry eats 3 red jellybeans and 6 yellow jellybeans, there are 3x - 3 red jellybeans and 4x - 6 yellow jellybeans left. The new ratio of red to yellow is given as 4:5, so we can set up an equation:

(3x - 3)/(4x - 6) = 4/5

To solve for x, we can cross-multiply and simplify:

5(3x - 3) = 4(4x - 6)

15x - 15 = 16x - 24

x = 9

Now we know that the original number of yellow jellybeans was 4x = 36.