Tim has thrice as many marbles as Justin. Justin has 9 more marbles than Eric. They have a total of 66 marbles.
- How many marbles does Tim have?
- How many marbles does Eric have?
(a)
Number of marbles that Justin has = 1 u
Number of marbles that Eric has = 1 u - 9
Number of marbles that Tim has = 3 u
Total number of marbles
= 1 u + 1 u - 9 + 3 u
= 5 u - 9
5 u - 9 = 66
5 u = 66 + 9
5 u = 75
1 u = 75 ÷ 5 = 15
Number of marbles that Tim has
= 3 u
= 3 x 15
= 45
(b)
Number of marbles that Eric has
= 1 u - 9
= 15 - 9
= 6
Answer(s): (a) 45; (b) 6
