Carol is three times Alice’s age but only twice as old as Betty. Alice is twenty years younger than Carol. How old is Betty?  Pick.
A) 26	B) 29	C) 32	D) 28	E) 15
Beyond the obvious Algebra approach to this question, it can also be solved by TESTing THE ANSWERS.   We're told 3 facts about the relative ages of 3 people:   1) Carol's age is 3 times Alice's age   2) Carol's age is 2 times Betty's age   3) Carol is 20 years older than Alice   We're asked for BETTY'S age.   From the answer choices and the information provided, Carol can't be that old (The difference of 20 years = 3 times; that relationship can only occur when the numbers are relatively small). Since Carol is TWICE Betty's age, Betty is clearly younger than Carol, so we'll TEST a smaller answer first.   IF....   Betty = 15   Then Carol = 2(15) = 30   Then Alice = 30 - 20= 
<gadget id="calculator">30 - 20</gadget>
<output>10</output>
10 AND   30/3= 
<gadget id="calculator">  30/3</gadget>
<output>10</output>
10   All of these values mesh perfectly with the facts and with one another, so Betty MUST be 15   15
<result>E</result>
Carol is three times Alice’s age but only twice as old as Betty. Alice is twenty years younger than Carol. How old is Betty?