There are 135 marbles in a bag. 0.2 of them are pink marbles, and the rest are black and red marbles. If there are 18 as many black marbles as red marbles. How many red marbles are there?
| Pink marbles |
Black marbles |
Red marbles |
Total |
| 1 u |
4 u |
5 u |
| |
1 p |
8 p |
|
0.2 =
210 =
15 Fraction of marbles that are black and red marbles
= 1 -
15 =
45 Total number of marbles = 5 u
5 u = 135
1 u = 135 ÷ 5 = 27
Number of black marbles and red marbles
= 4 u
= 4 x 27
= 108
Number of black and red marbles
= 1 p + 8 p
= 9 p
9 p = 108
1 p = 108 ÷ 9 = 12
Number of red marbles
= 8 p
= 8 x 12
= 96
Answer(s): 96
