David, Xavier, Daniel and Billy bought a notebook for their aunt. David paid
13 of what the rest paid. Xavier paid
14 of what the rest paid. Daniel paid
16 of what the rest paid. Billy paid $44 more than David. How much did the notebook cost?
David |
Xavier |
Daniel |
Billy |
Total |
1x35 |
|
|
|
4x35 |
|
1x28 |
|
|
5x28 |
|
|
1x20 |
|
7x20 |
35 u |
28 u |
20 u |
57 u |
140 u |
The cost of the notebook is repeated. Make the cost of the notebook the same. LCM of 4, 5 and 7 is 140.
Amount that Billy had
= 140 u - (35 u + 28 u + 20 u)
= 57 u
Amount that Billy paid more than David
= 57 u - 35 u
= 22 u
22 u = 44
1 u = 44 ÷ 22 = 2
Cost of the notebook
= 140 u
= 140 x 2
= $280
Answer(s): $280