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Thursday, January 17, 2008

MGS (Paya Lebar) Pri School P6 Math CA1 2006 (Q40)

The ratio of the amount of savings that Lisa had to the amount of savings that Andrea had was 8 : 5. They decided to share the cost of a Sony playstation in the ratio of 3 : 1. Lisa used half of her savings to pay for her share and Andrea paid $120 for her share. What was their total savings after paying for the playstation?


Solution

Ratio in which Linda and Andrea shared was 3 : 1.

(Lisa) 3 units
(Andrea) 1 unit ----- $120

Therefore Lisa,
3 units ----- 3 x $120 = $360

But $360 is half of Linda’s savings.
Therefore Lisa’s total savings ----- $360 x 2 = $720


Ratio of Lisa’s savings to Andrea’s was 8 : 5.
We also know that Lisa’s savings was $720.



Their savings after paying for the playstation

$360 + $330 = $690

Answer: They had a balance of $690 in total.

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