Harry, Ian, Albert and David bought a notebook for their aunt. Harry paid
13 of what the rest paid. Ian paid
14 of what the rest paid. Albert paid
16 of what the rest paid. David paid $66 more than Harry. How much did the notebook cost?
Harry |
Ian |
Albert |
David |
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 David had
= 140 u - (35 u + 28 u + 20 u)
= 57 u
Amount that David paid more than Harry
= 57 u - 35 u
= 22 u
22 u = 66
1 u = 66 ÷ 22 = 3
Cost of the notebook
= 140 u
= 140 x 3
= $420
Answer(s): $420