Question

a vendor buys oranges at 9 for rs. 10 and sells them at 12for rs.16 . find his gain percent

Answer 1

if CP of 9 =10 then
CP of one will be for =10/9=it will come in point
SP of 12=16 therefore
SP of one will be for 16 /12=it will also come in point
Then the SP will come greater than the CP;

So

P=SP-CP
P%=P of CP * 100