3 years ago, the average age of P and Q was 20years. With R joining them, theiraverage age becomes 23years. What is the age of R?  Choose the correct option
A) 18 years	B) 20 years	C) 21years	D) 23 years	E) 30 years
Three years ago, the average age of P and Q was 20 years.   Three years ago, their sum of the ages was 2x20= 40 years   Present age of P+Q+R = 3 X23 =69   Present age of P+Q=40+( 2 x 3)= 46   Present age of R = ( P+Q+R)- (P+Q)= 69-46= 
<gadget id="calculator">69-46</gadget>
<output>23</output>
23 years   23 years
<result>D</result>
3 years ago, the average age of P and Q was 20years. With R joining them, theiraverage age becomes 23years. What is the age of R?