Riordan has some silver and white marbles. The total mass of all his marbles is 214 g. He has 10 more white marbles than silver marbles. The average mass of the silver marbles is 5 g. The average mass of the white marbles is 6 g. How many marbles does Riordan have altogether?
| |
Silver |
White |
Total |
| Number |
1 u |
1 u + 10 |
2 u + 10 |
| Value |
5 |
6 |
|
| Total value |
5 u |
6 u + 60 |
214 |
Total mass of silver marbles
= 1 u x 5
= 5 u
Total mass of white marbles
= 6(1 u + 10)
= 6 u + 60
Total mass of the marbles
= 5 u + 6 u + 60
= 11 u + 60
11 u + 60 = 214
11 u = 214 - 60
11 u = 154
1 u = 154 ÷ 11 = 14
Total number of marbles
= 2 u + 10
= 2 x 14 + 10
= 28 + 10
= 60
Answer(s): 60
