Reggie has some green and pink marbles. The total mass of all his marbles is 230 g. He has 8 more pink marbles than green marbles. The average mass of the green marbles is 7 g. The average mass of the pink marbles is 15 g. How many marbles does Reggie have altogether?
| |
Green |
Pink |
Total |
| Number |
1 u |
1 u + 8 |
2 u + 8 |
| Value |
7 |
15 |
|
| Total value |
7 u |
15 u + 120 |
230 |
Total mass of green marbles
= 1 u x 7
= 7 u
Total mass of pink marbles
= 15(1 u + 8)
= 15 u + 120
Total mass of the marbles
= 7 u + 15 u + 120
= 22 u + 120
22 u + 120 = 230
22 u = 230 - 120
22 u = 110
1 u = 110 ÷ 22 = 5
Total number of marbles
= 2 u + 8
= 2 x 5 + 8
= 10 + 8
= 120
Answer(s): 120
