There are 200 marbles in a box. 0.2 of them are gold marbles, and the rest are red and purple marbles. If there are 37 as many red marbles as purple marbles. How many purple marbles are there?
| Gold marbles |
Red marbles |
Purple marbles |
Total |
| 1 u |
4 u |
5 u |
| |
3 p |
7 p |
|
0.2 =
210 =
15 Fraction of marbles that are red and purple marbles
= 1 -
15 =
45 Total number of marbles = 5 u
5 u = 200
1 u = 200 ÷ 5 = 40
Number of red marbles and purple marbles
= 4 u
= 4 x 40
= 160
Number of red and purple marbles
= 3 p + 7 p
= 10 p
10 p = 160
1 p = 160 ÷ 10 = 16
Number of purple marbles
= 7 p
= 7 x 16
= 112
Answer(s): 112
