plz solve this

Question

a shopkeeper has three different types of qualities of fruits, each of 20$, 24$ and 30$ per kg. If the first two qualities of fruits are mixed in the ratio 2:1, in what ratio should the three types of fruits be mixed so that the mixture can be sold at 28$ per kg?

Answer 1

20$*2 +24$*1 +30$*x=28*(x+2+1)

40+24 +30x=28x+3*28

30x-28x=84-64

2x=20

x=40