Suppose in one year total revenues from digital sales of pop

Suppose in one year, total revenues from digital sales of pop/rock, tropical (salsa/merengue/cumbia/bachata), and urban (reggaeton) Latin music in a certain country amounted to $24 million. Pop/rock music brought in twice as much as the other two categories combined and $9 million more than tropical music. How much revenue was earned from digital sales in each of the three categories

Solution

Ans: Suppose P, T & U represent pop tropical & urban music respectively. Then

P + T + U = 24 & P = 2 (T+U) which gives 3 ( T+U) = 24 T+U = 8. So P = 2*8 = 16.

Also P = T+9 . As P = 16 then T = 7 & as T+U = 8. So U = 1.

So P = 16, T = 7, U = 1.