There are 120 marbles in a basket. 0.4 of them are purple marbles, and the rest are black and red marbles. If there are 35 as many black marbles as red marbles. How many red marbles are there?
| Purple marbles |
Black marbles |
Red marbles |
Total |
| 2 u |
3 u |
5 u |
| |
3 p |
5 p |
|
0.4 =
410 =
25 Fraction of marbles that are black and red marbles
= 1 -
25 =
35 Total number of marbles = 5 u
5 u = 120
1 u = 120 ÷ 5 = 24
Number of black marbles and red marbles
= 3 u
= 3 x 24
= 72
Number of black and red marbles
= 3 p + 5 p
= 8 p
8 p = 72
1 p = 72 ÷ 8 = 9
Number of red marbles
= 5 p
= 5 x 9
= 45
Answer(s): 45
