Question

A shopkeeper keeps 100 marbles in two boxes, A and B, such that Box A contains only red and Box B contains only green marbles. Barring an equal number of marbles from each box, he sold all the others and earned Rs. 25 and Rs. 15 from Box A and Box B respectively. Later, he sold half of the remaining marbles. His total earning from all the transactions accumulated to Rs. 45. What is the cost of each marble - red or green.?

• A. 40 paise
• B. 25 paise
• C. 75 paise
• D. 50 paise

Answer 1

The correct option is D

50 paise

Let the number of red and green marbles be a and b respectively.

Let the selling price of each marble be Rs.e.

Let the equal number of marbles not sold the first time = c.

Then, e(a - c) = 25 ... (i)

e(b - c) = 15 ... (ii)

The number of marbles that remained that remained with the shopkeeper = 2c

e(a - c) + e(b - c) + ec = 45

ec = 5 ...(iii) (from (i) and (ii))

Also, (100 - c)e - 45

$\Rightarrow$ 100e - 5 = 45 (from (iii)

100e = 50

$\Rightarrow$ e = 0.5 = 50 Paise.

Hence, [d].