There are 120 marbles in a bag. 0.4 of them are green marbles, and the rest are gold and grey marbles. If there are 35 as many gold marbles as grey marbles. How many grey marbles are there?
Green marbles |
Gold marbles |
Grey marbles |
Total |
2 u |
3 u |
5 u |
|
3 p |
5 p |
|
0.4 =
410 =
25 Fraction of marbles that are gold and grey marbles
= 1 -
25 =
35 Total number of marbles = 5 u
5 u = 120
1 u = 120 ÷ 5 = 24
Number of gold marbles and grey marbles
= 3 u
= 3 x 24
= 72
Number of gold and grey marbles
= 3 p + 5 p
= 8 p
8 p = 72
1 p = 72 ÷ 8 = 9
Number of grey marbles
= 5 p
= 5 x 9
= 45
Answer(s): 45