18 copies of a book were sold for Rs.1260/- thereby gaining cost price of 3 copies. The cost price of a copy is:
Answer & explanation
Correct answer: option 1
Profit = S.P. of 18 - C.P. of 18
C.P. of 3 = S.P. of 18 - C.P. of 18
C.P. of 21 = S.P. of 18
C.P. : S.P.
18 : 21
⇓ ⇓ ×60
⇓ ×60 1260 (given)
(18 × 60)
C.P of 18 articles = 18 × 60
C.P. of each article = Rs.60/-