There was an equal number of pears and starfruits. On Saturday, some pears were added, such that the number of pears increased by 80%. On Sunday, the number of pears further increased by 50% and the number of starfruits decreased by 10%. There were 72 more pears than starfruits in the end. How many pears and starfruits were there altogether at first?
|
Pears |
Starfruits |
Before |
1 u |
1 u |
Change 1 |
+ 0.8 u |
No change |
After 1 |
1.8 u |
1 u |
Change 2 |
+ 0.9 u |
- 0.1 u |
After 2 |
2.7 u |
0.9 u |
Number of pears added on Saturday
= 80% x 1 u
=
80100 x 1 u
= 0.8 u
Number of pears increased on Sunday
= 50% x 1.8 u
=
50100 x 1.8 u
= 0.9 u
Number of starfruits decreased on Sunday
= 10% x 1 u
=
10100 x 1 u
= 0.1 u
Number of more pears than starfruits in the end
= 2.7 u - 0.9 u
= 1.8 u
1.8 u = 72
1 u = 72 ÷ 1.8 = 40
Total number of pears and starfruits at first
= 1 u + 1 u
= 2 u
= 2 x 40
= 80
Answer(s): 80