Adam and Rahmad shared some beads. If Adam gave 1/3 of his share to Rahmad, Rahmad would have 70 more than Adam. If Adam gave 1/5 of his share to Rahmad, Rahmad would have 10 more than Adam. How many beads does Adam have at first?
If Adam gave 1/3 of his share to Rahmad...
A [----][----]
R [----][----][ 70 ]
Which means that Adam will have 2 units left while Rahmad will have 2 units plus 70 more.
Adam would have a total of 3 units at first.
If Adam gave 1/5 of his share to Rahmad....
A [--][--][--][--]
R [--][--][--][--][ 10]
Which means that Adam will have 4 units (different from the first model) left while Rahmad will have 4 units plus 10 more.
Adam would have a total of 5 units at first.
BASED ON SAME TOTAL for Adam (3 x 5 = total 15 units),
We can change the units into....
If Adam gave 1/3 of his share to Rahmad...
All units multiply by 5 to get a total of 15 units at first:
A [-][-][-][-][-][-][-][-][-][-]
R [-][-][-][-][-][-][-][-][-][-][ 70 ]
If Adam gave 1/5 of his share to Rahmad....
All units multiply by 3 to get a total of 15 units at first:
A [-][-][-][-][-][-][-][-][-][-][-][-]
R [-][-][-][-][-][-][-][-][-][-][-][-][ 10]
Comparing the above 2 models, we can see that 4 units = 70 - 10 = 60
1 unit = 60/4 = 15
15 units = 15 x 15 = 225
From: http://www.kiasuparents.com/kiasu/forum/viewtopic.php?t=280&postdays=0&postorder=asc&start=2320
The school teacher's answer is 450 which many parents have debated to be wrong.
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