Question

by selling a table for rs.1320 a trader gains 10 percent.. find the CP of the table

Answer 1

CP = {100/(100 + gain%)} × SP 

Therefore:
cp =rs {100/100+10}*sp
cp =rs {100/110}*1320
cp =rs 1220

Answer 2

Let the CP of the table be    rs.x
Given SP = rs.1320
Gain% = 10%
We know that
CP = SP - Gain%
⇒x = 1320 - (10/100) ×  x
⇒x = 1320 - (1/10) × x
⇒x = 1320 - x/10
⇒x + x/10 = 1320
⇒(10x + x)/10 =1320
⇒11x = 1320 × 10
⇒11x = 13200
⇒ x = 13200/11
∴x = 1200
Therefore the cost price of the table is Rs 1200