Question

ravish bought 100 articles for rs. 4000.he sold 40 of them at a gain of 5%. at what gain per cent must he sell the remaining articles so as to gain 20% on the whole?

Answer 1

Firstly we have to find
4000+ 4000×20%=rs.4800
Total profit =total sp- total cp
=4800-4000
=rs.800
since 100 articles = 800 gain
therefore 1...........= 800/100
= rs.8
100 articles = rs 4000
now
1 article = 4000/100
Rs.= 40
Therefore 40......= rs.1600
Gain at 5% on rs.1600
1600+1600×5%=1680
new sp=4800- 1680
=rs.3120
now sp of 60 articles =3120
cp of 60 articles = 40×60=rs.2400
therefore new gain = 3120- 2400 =720
Gain % on 2460 = 720/2400 ×100
=30 %