The cost of 15 apples & 20 mangoes is much as equal to the 15 mangoes & 20 apples

Q: The cost of 15 apples & 20 mangoes is much as equal to the 15 mangoes & 20 apples then what is the relation between their costs ratio ?
A)1:1
B)2:1
C)1:2
D)3:2

Answer: A

Let the cost of mango be M and apple be A
construct the following equations by the data given,
15A+20M=C———eq(1) where C-cost
20A+15M=C———eq(2)
solving the equations we get
A=M
so the cost of apple and mango are same.
hence cost ratio is 1:1