A box contains some kiwis, starfruits and oranges. 0.4 of the kiwis is equal to 30% of the starfruits. The number of oranges is ³₄ of the total number of starfruits and kiwis. If there are 50 more oranges than starfruits, how many fruits are there in the box altogether?

Kiwis	Starfruits	Oranges
3x4	4x4
4x7		3x7
12 u	16 u	21 u

0.4 = ⁴₁₀= ²₅
30% = ³⁰₁₀₀ = ³₁₀

0.4 of the kiwis is equal to 30% of the starfruits. Make the numerators the same.  LCM of 2 and 3 is 6.

2x35x3 of the kiwis = 3x210x2 of the starfruits
615 of the kiwis = 620 of the starfruits 

Kiwis : Starfruits
15 : 20 _(÷5)
3 : 4

The total number of kiwis and starfruits is repeated.  Make the total number of kiwis and starfruits the same.  LCM of 7 and 4 is 28.

Number of more oranges than starfruits
= 21 u - 16 u
= 5 u

5 u = 50

1 u = 50 ÷ 5 = 10

Number of the fruits in the box altogether
= 12 u + 16 u + 21 u
= 49 u
= 49 x 10
= 490

Answer(s): 490