Pens at 20 Rs each and books at 40 Rs each were purchased. In all these were 6, at a total cost of Rs.180. If the number of Pens and books were interchanged, how much less would have been spent ?

0

same amount

Rs.2.50

Rs.6

Correct Answer : D

If ( p - q) ^{2} = ( x – y ) ^{2}, then x =