C) A shopkeeper made a loss of Rs 20 when he sold a bag at 20% discount. If he had sold it at 10% discount, he would have gained 8%. Find the marked price of the bag. help!!

Marked price Rs. 600

Step-by-step explanation:

Let M be the marked price

1) When shop keeper sold at 20% discount, ie. SP = 0.8M

CP - SP = 20

CP = 20 + SP

CP = 20 + 0.8M

2) When shopkeeper sells at 8% discount, he makes a profit of 10%

SP = 0.9M/1.08

Equating 1 and 2, we get

20 + 0.8M = 0.9M/1.08

21.6 + 0.864M = 0.9M

0.036 M = 21.6

M = 21.6 / 0 036

M = 600