There are 128 marbles in a box. 0.5 of them are brown marbles, and the rest are black and white marbles. If there are 17 as many black marbles as white marbles. How many white marbles are there?
| Brown marbles |
Black marbles |
White marbles |
Total |
| 1 u |
1 u |
2 u |
| |
1 p |
7 p |
|
0.5 =
510 =
12 Fraction of marbles that are black and white marbles
= 1 -
12 =
12 Total number of marbles = 2 u
2 u = 128
1 u = 128 ÷ 2 = 64
Number of black marbles and white marbles
= 1 u
= 1 x 64
= 64
Number of black and white marbles
= 1 p + 7 p
= 8 p
8 p = 64
1 p = 64 ÷ 8 = 8
Number of white marbles
= 7 p
= 7 x 8
= 56
Answer(s): 56
