Question
( 12 mathrm{sp}=₹ 1800 )
gain ( =3 times 0 )
gain ( =(5 mathrm{P}-mathrm{cP}) 12 )
( begin{aligned} 3 mathrm{cp} &=1800-12 mathrm{cp} 15 mathrm{c} &=1800 end{aligned} )
[
begin{aligned} mathrm{cp}=& ₹ 120 end{aligned}
]

21. 12 copies of a book were sold for 1800 thereby gaining cost price of 3 copies. The cost price of a copy of the books is (1) * 120 (2) * 150 (3) 1200 (4) 1500
Solution
