Question

MP of an article is Rs. 1200. A shopkeeper give two
successive discount on MP. If one discount is 30 %n and selling
price of an article is Rs. 672. Find second discount %.

Answer 1

1st discount is 30% then remaining value aftr 30%discount =1200×70/100=840

now ... let the 2nd discount is =y% and discount is (840-672)=168

according to question

840×y%=168

840×y/100=168

y=168×100/840

y=168×10/84

y=14×10/7

y=20%

or

when X and y are successive discount then .. equivalent discount is=(x+y)-xy/100

in this question equivalent

discount=(30+y)-30y/100

and we know that real discount is=1200-672= 528 .

in% =528×100/1200 = 44%

now, (30+y)-30y/100=44.

y=20%