Ben has some pink and red marbles. The total mass of all his marbles is 186 g. He has 6 less pink marbles than red marbles. The average mass of the pink marbles is 8 g. The average mass of the red marbles is 10 g. How many marbles does Ben have altogether?
| |
Pink |
Red |
Total |
| Number |
1 u |
1 u + 6 |
2 u + 6 |
| Value |
8 |
10 |
|
| Total value |
8 u |
10 u + 60 |
186 |
Total mass of pink marbles
= 1 u x 8
= 8 u
Total mass of red marbles
= 10(1 u + 6)
= 10 u + 60
Total mass of the marbles
= 8 u + 10 u + 60
= 18 u + 60
18 u + 60 = 186
18 u = 186 - 60
18 u = 126
1 u = 126 ÷ 18 = 7
Total number of marbles
= 2 u + 6
= 2 x 7 + 6
= 14 + 6
= 60
Answer(s): 60
