swerve wrote:A digital camera salesman earns a commision of $12 per camera for the first 10 cameras he sells each day. If the salesman earns a commision of $16 a camera for each one sold over 10, How many cameras did he sells today?

(1) Yesterday the camera salesman sold 10 cameras.
(2) The salesman earned $48 in commision more today than yesterday.

The OA is C.

Please, can anyone explain this DS question? I tried to solve it but I don't understand why C is the correct answer. I need help. Thanks.

1. Commission, if sales ≤ 10 = $12 per camera
2. Commission, if sales > 10 = $(12*10 + 16x) per camera, where x = number of cameras sold above 10

Let's take each statement one by one.

(1) Yesterday the camera salesman sold 10 cameras.

No information about today's sale. Insufficient.

(2) The salesman earned $48 in commision more today than yesterday.

No information about yesterday's sale. Insufficient.

(1) and (2) together

From 1, we know that he sold 10 cameras yesterday; since he earned $48 in commision more today than yesterday, he must have sold more than 10 cameras today.

=> 48 = 16*x => x = 3 cameras.

Total number of cameras sold today = 10 + 3 = 13. Sufficient.

The correct answer: C

Hope this helps!

-Jay
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