Oscar bought 18 more marbles than Tim and Tim bought 15 marbles more than Andy. The total number of marbles Oscar and Tim bought was 5 times the number of marbles Andy bought.
- How many marbles does Oscar need to give Tim so that they have the same number of marbles?
- How many marbles did all three of them have altogether?
(a)
Since Oscar had 18 marbles more than Tim, Oscar needed to give half of his extra marbles to Tim.
Number of marbles that Oscar needs to give to Tim
= 18 ÷ 2
= 9
(b)
Number of marbles that Andy bought = 1 u
Number of marbles that Tim bought = 1 u + 15
Number of marbles that Oscar bought
= 1 u + 15 + 18
= 1 u + 33
Number of marbles that Tim and Oscar bought
= 1 u + 15 + 1 u + 33
= 2 u + 48
Total number of marbles that Oscar and Tim bought is 5 times the number that Andy bought.
Number of marbles that Tim and Oscar bought = 5 u
5 u = 2 u + 48
5 u - 2 u = 48
3 u = 48
1 u = 48 ÷ 3 = 16
Total number of marbles
= 5 u + 1 u
= 6 u
= 6 x 16
= 96
Answer(s): (a) 9; (b) 96
