Dylan has some green and red marbles. The total mass of all his marbles is 182 g. He has 6 less green marbles than red marbles. The average mass of the green marbles is 3 g. The average mass of the red marbles is 7 g. How many marbles does Dylan have altogether?
| |
Green |
Red |
Total |
| Number |
1 u |
1 u + 6 |
2 u + 6 |
| Value |
3 |
7 |
|
| Total value |
3 u |
7 u + 42 |
182 |
Total mass of green marbles
= 1 u x 3
= 3 u
Total mass of red marbles
= 7(1 u + 6)
= 7 u + 42
Total mass of the marbles
= 3 u + 7 u + 42
= 10 u + 42
10 u + 42 = 182
10 u = 182 - 42
10 u = 140
1 u = 140 ÷ 10 = 14
Total number of marbles
= 2 u + 6
= 2 x 14 + 6
= 28 + 6
= 42
Answer(s): 42
