There are 200 balls in a bag. 0.2 of them are grey balls, and the rest are black and gold balls. If there are 14 as many black balls as gold balls. How many gold balls are there?
| Grey balls |
Black balls |
Gold balls |
Total |
| 1 u |
4 u |
5 u |
| |
1 p |
4 p |
|
0.2 =
210 =
15 Fraction of balls that are black and gold balls
= 1 -
15 =
45 Total number of balls = 5 u
5 u = 200
1 u = 200 ÷ 5 = 40
Number of black balls and gold balls
= 4 u
= 4 x 40
= 160
Number of black and gold balls
= 1 p + 4 p
= 5 p
5 p = 160
1 p = 160 ÷ 5 = 32
Number of gold balls
= 4 p
= 4 x 32
= 128
Answer(s): 128
