A bag containing 5 red balls, 8 blue balls and 7 yellow balls, what % of the balls are blue?

5+7+8=20 which is the total number of balls that the bag contains
because out of the 20 balls only the 8 are blue, it is right to say that

8/20 = x/100 ⇒ x= (8·100)/20 ⇒ x= 800/20 ⇒ x=40

the blue balls are the 40%

Answer Link

TheBlueFox TheBlueFox · Answer 2 · 2019-07-19T12:36:08-04:00

There are 20 balls in the bag altogether.

If 12 of them are not blue, that means that 8 of them are blue. We can find out what percent of the blue balls are in the bag by turning it into a fraction.

The fraction \(\frac{8}{20}\) represents the 8 blue balls out of the 20 balls altogether.

Now that we have our fraction, we can change it into a percent. The fraction \(\frac{8}{20}\) can be reduced to \(\frac{2}{5}\) by dividing both the numerator and denominator by the greatest common factor.

2 ÷ 5 = 0.4

0.4 x 100 = 40%

40% of the balls in the bag are blue.