There were some mangoes at a shop. In the morning,
15 of mangoes were sold. In the afternoon, another 28 mangoes were sold. The total number of mangoes left was 5 less than
512 of the number of mangoes the shop had at first.
- How many mangoes were there at first?
- What fraction of the mangoes in the shop remained unsold in the afternoon?
|
Comparison 1 |
Comparison 2 |
Before |
5x12 = 60 u |
12x5 = 60 u |
Change 1 |
- 1x12 = - 12 u |
|
After 1 |
4x12 = 48 u |
Change 2 |
- 28 |
After 2 |
48 u - 28 |
5x5 - 5 = 25 u - 5 |
(a)
The number of mangoes at first is repeated in both comparisons. Make the number of mangoes at first. LCM of 5 and 12 is 60.
The number of mangoes in the end is the same in both comparisons.
48 u - 28 = 25 u - 5
48 u - 25 u = 28 - 5
23 u = 23
1 u = 23 ÷ 23 = 1
Number of mangoes at first
= 60 u
= 60 x 1
= 60
(b)
Number of mangoes that remained unsold
= 48 u - 28
= 48 x 1 - 28
= 48 - 28
= 20
Fraction of mangoes that remained unsold
=
2060=
13Answer(s): (a) 60; (b)
13