Tommy has some brown and yellow marbles. The total mass of all his marbles is 192 g. He has 6 more yellow marbles than brown marbles. The average mass of the brown marbles is 4 g. The average mass of the yellow marbles is 8 g. How many marbles does Tommy have altogether?
| |
Brown |
Yellow |
Total |
| Number |
1 u |
1 u + 6 |
2 u + 6 |
| Value |
4 |
8 |
|
| Total value |
4 u |
8 u + 48 |
192 |
Total mass of brown marbles
= 1 u x 4
= 4 u
Total mass of yellow marbles
= 8(1 u + 6)
= 8 u + 48
Total mass of the marbles
= 4 u + 8 u + 48
= 12 u + 48
12 u + 48 = 192
12 u = 192 - 48
12 u = 144
1 u = 144 ÷ 12 = 12
Total number of marbles
= 2 u + 6
= 2 x 12 + 6
= 24 + 6
= 48
Answer(s): 48
