There were some starfruits at a market. In the morning,
14 of starfruits were sold. In the afternoon, another 21 starfruits were sold. The total number of starfruits left was 9 less than
512 of the number of starfruits the market had at first.
- How many starfruits were there at first?
- What fraction of the starfruits in the market remained unsold in the afternoon?
|
Comparison 1 |
Comparison 2 |
Before |
4x3 = 12 u |
12x1 = 12 u |
Change 1 |
- 1x3 = - 3 u |
|
After 1 |
3x3 = 9 u |
Change 2 |
- 21 |
After 2 |
9 u - 21 |
5x1 - 9 = 5 u - 9 |
(a)
The number of starfruits at first is repeated in both comparisons. Make the number of starfruits at first. LCM of 4 and 12 is 12.
The number of starfruits in the end is the same in both comparisons.
9 u - 21 = 5 u - 9
9 u - 5 u = 21 - 9
4 u = 12
1 u = 12 ÷ 4 = 3
Number of starfruits at first
= 12 u
= 12 x 3
= 36
(b)
Number of starfruits that remained unsold
= 9 u - 21
= 9 x 3 - 21
= 27 - 21
= 6
Fraction of starfruits that remained unsold
=
636=
16Answer(s): (a) 36; (b)
16