12 copies of a book were sold for ₹1800/- thereby gaining cost price of 3 copies. The cost price of a copy is:
Answer & explanation
Correct answer: option 1
Profit = S.P. of 12 - C.P. of 12
C.P. of 3 = S.P. of 12 - C.P. of 12
C.P. of 15 = S.P. of 12
C.P. : S.P.
12 : 15
⇓ ⇓ × 120
⇓ × 120 1800 (given)
(12× 120)
C.P of 12 articles = 12 × 120
C.P. of each article = Rs.120/-