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

p–q+y

y – p + q

Both ( a) and (b)

None of these

Correct Answer : A

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 ?