Sandy gets 3 marks for each correct sum and loses 2 marks for each incorrect sum. Sandy attempts 30 sums and obtains 60 marks. How many sums did Sandy get correct?	Pick.
A) 18
B) 20
C) 22
D) 24
E) 26
Let x be the correct sums and (30-x) be the incorrect sums.   3x - 2(30-x) = 60   5x = 120   x = 24   The answer is 24.
<result>D</result>
Sandy gets 3 marks for each correct sum and loses 2 marks for each incorrect sum. Sandy attempts 30 sums and obtains 60 marks. How many sums did Sandy get correct?