Question

In a bag,There are red and blue cubes in the ratio 4:7.I add 10 more red cubes to the bag.Now here are red and blue cubes in the ratio 6:7.How many blue cubes are in the bag?

Answer 1

Given:

The ratio of red and blue cubes is 4:7.

After adding 10 more red cubes the ratio of red and blue cubes is 6:7.

To find:

The number of blue cubes.

Solution:

The ratio of red and blue cubes is 4:7.

Let the number of red and blue cubes be 4x and 7x respectively.

After adding 10 more red cubes.

Number of red cubes = 4x+10

Then, the ratio of red and blue cubes is 6:7.

`(4x+10)/(7x)=(6)/(7)`

`7(4x+10)=6(7x)`

`28x+70=42x`

`70=42x-28x`

`70=14x`

Divide both sides by 14.

`5=x`

Now,

Number of blue cubes in the bag is

`7(5)=35`

Therefore, the number of blue cubes is 35.