Data Sufficiency

The cost of each adult's ticket for a certain concert was 30$,and the cost of each childs's ticket for the concert was 24$.If Hannah purchased tickets for this concert,what was the average (arithematic mean) cost per ticket?

1)Hannah purchased twice as many children's tickets as adults' tickets.

2)Hannah purchased 4 children's tickets.


OA-A

Adult's Ticket = $30, Child's Ticket = $24.

Number of Adult's tickets = x, Number of Child's tickets = y.

We need to find (30x + 24y)/(x+y).

Stmt1: y = 2x
(30x + 24y)/(x+y) = (30x + 24*2x)/(x+2x)
= 78x/3x
=26. Sufficient.

Stmt2: y = 4.
No information about x (number of adult's tickets) or total tickets. Insufficient.

Hence A.

o jeez !

forgot to covert the denom into terms of x

thanks.