Rita bought a television set with 20% discount on the labelled price. She made a profit of ? 800 by selling it for ? 16800. The labelled price of the set was

Here, r = 20% and r₁ = 15%
Required profit per cent =[ r(100 - r₁)/100] - r₁
= [20(100 - 15)/100] - 15
= 17 - 15
= 2%

? Single discount equivalent to 36% and 4%
= 36 + 4 - {(36 x 4)/100} = 38.56

? Required difference
= {(40 - 38.56) x 500}/100 = 1.44 x 5 = ? 7.20

? Marked price of a shirt = ? 320
Discount on a shirt = 320 x 25/100 = ? 80

? Number of shirts has to be purchased to get a rebate of ? 400 = 400/80 = 5

Let the marked price of item = ? N
? {(100 - 14) /100 } of N = 645
? N = (645 x 100)/86 = ? 750

Here, r₁ = 10 %, r₂ = 20% and r₃ = 30%
? Required discount
= [1 - (1 - r₁/100) (1 - r₂/100) (1 - r₃/100)] x 100%
= [1 - (1 -10/100) (1 - 20/100) (1 - 30/100)] x 100%
= {1 - (9/10) x (4/5) x (7/10)} x 100%
= (1 - 0.504) x 100% = 49.6%

? Marked price of an article = ? 500
The selling price of article after discount 20% and 10%
= 500 x {(100 - 20) / 100} x {(100 - 10) / 100}
= 500 x (80/100) x (90/100)
= ? 360

Here, r₁ = 20% and r₂ = 5%
? Required percentage
= r₁ + r₂ - (r₁ x r₂)/100%
= 20 + 5 - (20 x 5)/100
= 25 - 1
=24%