There are 105 marbles in a bag. 0.2 of them are brown marbles, and the rest are grey and gold marbles. If there are 15 as many grey marbles as gold marbles. How many gold marbles are there?
Brown marbles |
Grey marbles |
Gold marbles |
Total |
1 u |
4 u |
5 u |
|
1 p |
5 p |
|
0.2 =
210 =
15 Fraction of marbles that are grey and gold marbles
= 1 -
15 =
45 Total number of marbles = 5 u
5 u = 105
1 u = 105 ÷ 5 = 21
Number of grey marbles and gold marbles
= 4 u
= 4 x 21
= 84
Number of grey and gold marbles
= 1 p + 5 p
= 6 p
6 p = 84
1 p = 84 ÷ 6 = 14
Number of gold marbles
= 5 p
= 5 x 14
= 70
Answer(s): 70