PSLE A shop had a number of hi-fi systems for sale. After selling 20 of them in the morning and
25 of the remainder in the afternoon, it was left with
15 of the hi-fi systems. How many hi-fi systems were sold altogether?
Morning |
Remainder |
|
Afternoon |
Left |
20 |
2x1 |
3x1 |
4x3 |
1x3 |
10 u |
2 u |
3 u |
Fraction of the remainder left
= 1 -
25 =
35 3x15x1 Remainder =
1x35x3 Total
35 Remainder =
315 Total
Number of hi-fi systems sold in the morning
= 12 u - 2 u
= 10 u
10 u = 20
1 u = 20 ÷ 10 = 2
Total number of hi-fi systems sold
= 12 u
= 12 x 2
= 24
Answer(s): 24