2/5 of the number of apples is equal to 3 times the number of mangoes. What is the ratio of the number of apples to the total number of fruits?

2/5 a = 3 m

2a = 15 m
a = 7.5 m
so we want
a / (a+m)
= 7.5 m / (7.5 m + m)= 7.5 /8.5