SBI PO – 2015 – 34

Question: A reduction of 20% in the price of salt enables a person to buy 8 kg more for Rs. 80. Find the reduced and the original price per kg of salt respectively. [नमक के मूल्य में 20% की कमी होने पर एक व्यक्ति 80 रूपये में 8 किग्रा नमक ज्यादा खरीद पाता है. नमक का घटा हुआ एवं प्रारंभिक मूल्य प्रति किग्रा क्रमशः बताएं.]      [Ans. (c) Rs. 2, Rs. 2.50]                                                                 

(a) Rs 2.50, Rs.2 (b) Rs 2.50, Rs 3 (c) Rs 2, Rs 2.50 (d) Rs 1.5, Rs 2 (e) None of these

Detailed Explanation:

First Method: Price of salt reduces by 20%, so 20% of Rs 80 = Rs 16

Extra salt available is 8 kg, when price reduces by 20%

So, 8 kg of salt costs Rs 16, then 1 kg of salt cost Rs 16/8 = 2 Rs/kg; which is reduced price Ans.

Now the Original Price can be determined by two methods

First Method

Second Method

Since reduction is 20%,

80 % ≡ 2 Rs/kg (Reduced Price)

100% ≡? = 2.50 Rs/kg (Original Price) Ans.

Second Method: Let the rate of salt is x Rs/kg.

When the price of salt reduces by 20%, the reduced rate becomes 80% of x = 4x/5 Rs/kg.

Initial quantity was 80/x kg; while quantity at the reduced rate is 80/(4x/5) kg. The difference is of 8 kg. So,