Question

After deducting 10 % from a sum and then 20 % from the remainder, there is Rs.3600 left. Find the original amount

Answer 1

Let the original amount be x

Deducting 10% of x we get....x-10%of x, or 90x/100

Now deducting 20% from 90x/100 we get 90x/100-20%of90x/100 which is

90x/100-90x/500

or, 360x/500, this is equal to 3600 as per the conditions

Therefore 360x=3600*500

or, x =3600*500/360 =5000 , the original amount is 5000

Answer 2

Let the original amount be x

Find the amount after deducting 10%:

10% of x = 0.1x

Amount left after deducting the 10% = x - 0.1x = 0.9x

Find the amount after deducing 20% from the remainder:

20% of 0.9x = (0.2)(0.9x) = 0.18x

Amount left after deducting the 20% = 0.9x - 0.18x = 0.72x

Given that the remainder is Rs 3600

⇒ 0.72x = 3600

Find the original amount:

0.72x = 3600

x = 3600 ÷ 0.72

x = Rs 5000

Answer: The original amount is Rs 5000