Joe bought only twenty cent stamps and thirty cent stamps. How many twenty cent stamps did he buy?
(1) Joe bought more than 8 twenty cent stamps.
(2) Joe bought a total of $2.50 worth of stamps.
The OA says C but I am getting B ..guys can you please explain
I applied my reasoning that .2x+.3y=2.50
Hence we add and we can get 2.50 ..so B should be sufficient..I tried but there are no other integer choices for this combination.
Please help ....
(1) Joe bought more than 8 twenty cent stamps --> clearly insufficient.
must be an integers we must check whether this equation has unique solution (for more on this check below links) -->
, so 25 minus multiple of 3 must be multiple of 2, following pairs of (x,y) are possible: (2, 7), (5, 5), (8, 3), (11, 1). Not sufficient.
P.S. Also you should have spotted that x=5 and y=5 for (2) is not correct solution as (1) says that x>8. So if x=5 were correct solution then statements would clearly contradict each other, but