If the sum of two numbers is 33 and their difference is 15, the smaller number is :__________?
A. 9
B. 12
C. 15
D. 18
Problems on Numbers
The sum of the squares of three numbers is 138, while the sum of their products taken two at a time is 131. Their sum is :___________?
A. 20
B. 30
C. 40
D. None of these