There are 162 balls in a box. 0.5 of them are grey balls, and the rest are white and brown balls. If there are 18 as many white balls as brown balls. How many brown balls are there?
| Grey balls |
White balls |
Brown balls |
Total |
| 1 u |
1 u |
2 u |
| |
1 p |
8 p |
|
0.5 =
510 =
12 Fraction of balls that are white and brown balls
= 1 -
12 =
12 Total number of balls = 2 u
2 u = 162
1 u = 162 ÷ 2 = 81
Number of white balls and brown balls
= 1 u
= 1 x 81
= 81
Number of white and brown balls
= 1 p + 8 p
= 9 p
9 p = 81
1 p = 81 ÷ 9 = 9
Number of brown balls
= 8 p
= 8 x 9
= 72
Answer(s): 72
