There was an equal number of grapefruits and lemons. On Monday, some grapefruits were added, such that the number of grapefruits increased by 60%. On Tuesday, the number of grapefruits further increased by 50% and the number of lemons decreased by 10%. There were 120 more grapefruits than lemons in the end. How many grapefruits and lemons were there altogether at first?

	Grapefruits	Lemons
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 Monday
= 60% x 1 u
= ⁶⁰₁₀₀ x 1 u
= 0.6 u

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

Number of lemons decreased on Tuesday
= 10% x 1 u
= ¹⁰₁₀₀ x 1 u
= 0.1 u

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

1.5 u = 120

1 u = 120 ÷ 1.5 = 80

Total number of grapefruits and lemons at first
= 1 u + 1 u
= 2 u
= 2 x 80
= 160

Answer(s): 160