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.
[tex]\dfrac{4x+10}{7x}=\dfrac{6}{7}[/tex]
[tex]7(4x+10)=6(7x)[/tex]
[tex]28x+70=42x[/tex]
[tex]70=42x-28x[/tex]
[tex]70=14x[/tex]
Divide both sides by 14.
[tex]5=x[/tex]
Now,
Number of blue cubes in the bag is
[tex]7(5)=35[/tex]
Therefore, the number of blue cubes is 35.
