A man bought goods worth Rs. 6000 and sold half of them at a gain of 10%. At what gain per cent must the sell the remainder to get a gain of 25% on the whole?
C.P. of 1st half of goods =12×6000= Rs. 3000
S.P. of 1st half of the goods =110100×3000= Rs. 3300
C.P. of 2nd half of goods = Rs. 3000
Let profit % =x
Then, S.P. of 2nd half of goods =(100+x100)×3000
Total CP. = Rs. 6000, Total gain =25%
∴ Total S.P. =125100×6000= Rs. 7500
Given, 3300+30(100+x)=7500
⇒30(100+x)=4200
⇒100+x=140
⇒x=40%