Question

A reduction of 21% in the price of wheat enable a person to buy 10.5 kg more for Rs.100 . what is the reduced price per kg​

Answer 1

Answer:

Rs. 2 per kg

Step-by-step explanation:

Let Original price= Rs. x per kg

The reduction percentage from the original price is 21 %.

So, the reduced price per kg= (x)×(79÷100)  ∵ [100-21% = 79%]

                                               = (79x/100)

for rs. x = can buy 1kg

for rs.100 = (100×1)÷x = (100/x) kg

as same as,

for rs. (79x/100)= can buy 1 kg

for rs.100= (100×1)÷(79x/100)= (100×100)÷(79x) = (10000/79x) kg

After reducing the price, can buy 10.5 kg more for rs. 100. It means, the difference between  purchasable quantity (kg) for rs.100 at original cost and reduced cost is 10.5

so, (10000/79x) - (100/x) = 10.5    

(10000-7900) = (10.5×79x)           ∵ [take 79x as LCM, and simplify]

x = (2100)÷(10.5×79)

[keep this value as it is. This is the original price. We need the reduced price]

The reduced price= 79x/100

                              = [79÷100] × [(2100)÷(10.5×79)]    

∵[Substitution of value of x]

                               = 2

So, the reduced price per kg = Rs. 2   (ans.)