Question

The cost of 10 pens is rs 500 . 2 pens are sold at rs 40 each. At what price should the remaining pens be sold so as to gain 20% on the whole?

Answer 1

CP of 10 pens=₹500
CP of 1 pen=500/10
CP=₹50

SP of 1 pen=₹40
2 pen=40+40=₹80

Gain should 20%

Means Now amount after gain
=500+(500×20/100)
=500+100
=₹600

Now SP of 8 pens=600-80
=₹520

Price of 1 pen=520/8
=₹65

So At ₹65 each pen should sell to gain 20%

Answer=₹520
Per /pen=₹65