Question

After allowing a discount of 20% on the marked price of a lamp, a trader loses 10%. By what percentage is the marked price above the cost price?

Answer 1

Given,

Let the cost price of the lamp be = Rs x

Then, SP = (100 – loss%)/100 × CP

= (100 – 10)/100 × x

= 90x/100

Now,

SP = Rs 90x/100 and Discount = 20%

By using the formula,

MP = (100×SP) / (100 – Discount%)

= (100×90x/100) / (100 – 20)

= 90x/80

= 9x/8

Required difference = MP – CP

= Rs (9x/8 – x)

= (9x-8x)/8

= Rs x/8

Discount% = (x/8)/x × 100

= 100/8

= 12.5%

∴ The trader must mark his goods 12.5% above the cost price.