There are 200 balls in a box. 0.4 of them are green balls, and the rest are grey and gold balls. If there are 37 as many grey balls as gold balls. How many gold balls are there?
| Green balls |
Grey balls |
Gold balls |
Total |
| 2 u |
3 u |
5 u |
| |
3 p |
7 p |
|
0.4 =
410 =
25 Fraction of balls that are grey and gold balls
= 1 -
25 =
35 Total number of balls = 5 u
5 u = 200
1 u = 200 ÷ 5 = 40
Number of grey balls and gold balls
= 3 u
= 3 x 40
= 120
Number of grey and gold balls
= 3 p + 7 p
= 10 p
10 p = 120
1 p = 120 ÷ 10 = 12
Number of gold balls
= 7 p
= 7 x 12
= 84
Answer(s): 84
