There was an equal number of grapefruits and chikoos. On Saturday, some grapefruits were added, such that the number of grapefruits increased by 60%. On Sunday, the number of grapefruits further increased by 50% and the number of chikoos decreased by 10%. There were 15 more grapefruits than chikoos in the end. How many grapefruits and chikoos were there altogether at first?

	Grapefruits	Chikoos
Before	1 u	1 u
Change 1	+ 0.6 u	No change
After 1	1.6 u	1 u
Change 2	+ 0.8 u	- 0.1 u
After 2	2.4 u	0.9 u

Number of grapefruits added on Saturday
= 60% x 1 u
= ⁶⁰₁₀₀ x 1 u
= 0.6 u

Number of grapefruits increased on Sunday
= 50% x 1.6 u
= ⁵⁰₁₀₀ x 1.6 u
= 0.8 u

Number of chikoos decreased on Sunday
= 10% x 1 u
= ¹⁰₁₀₀ x 1 u
= 0.1 u

Number of more grapefruits than chikoos in the end
= 2.4 u - 0.9 u
= 1.5 u

1.5 u = 15

1 u = 15 ÷ 1.5 = 10

Total number of grapefruits and chikoos at first
= 1 u + 1 u
= 2 u
= 2 x 10
= 20

Answer(s): 20