A dishonest dealer professes to sell his goods at Cost Price but still gets 20% profit by using a false weight. What weight does he substitute for a kilogram ?
A. 855 1/2 grams
B. 833 1/3 grams
C. 833 1/2 grams
D. 875 2/7 grams
Answer : B. 833 1/3 grams
Explanation:
Let the error is x gm. So we have
( error / True weight – error ) * 100 = %gain profit
= ( x / 1000 – x ) * 100 = 20
x / 1000 – x = 1 / 5
5x = 1000 – x
6x = 1000
x = 1000/6 gm
Hence the weight = 1000 – (1000 / 6)
833 1/3