Question

A man sold his radio-set at a loss of 20%.If he would have sold it for ₹90 more, his loss would have been only 10%. Find cost price of radio-set.

Answer 1

If the cost was c and the selling price was p,

p = 0.80c
p+90 = 0.90c

Now just solve for c.

Or, consider that the extra 90 is 10% of the cost. So, the cost was 900.