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# The shop keeper sells three different types of marbles. The Blue marbles cost 20 paise each, the Green ones cost 90 paise each and the Black ones cost 5 paise each. Each bag of marbles has 5 Black marbles, 1 Green marble and 2 Blue marbles. I bought a certain number of bags and paid Rs. 6.50 in all for the Blue and Green Marbles. How much did I pay for the Black marbles?

(A) Rs. 1.00 (B) Rs. 1.05 (C) Rs. 1.10 (D) Rs. 1.25

## 1 Answer Comment
A)
Let us first calculate the number of bags I must have purchased if I paid Rs. 6.50 for Blue and Green marbles.
One bag has 2 Blue marbles, 1 Green marble and 5 Black marbles.
Cost of 2 Blue marbles = 2 x 20 p = 40 p.
Cost of 1 Green marble = 90 p.
I spend Rs. 6.50 on Blue and Green marbles, therefore the number of bags I must have bought = $\large\frac{6.50}{1.30}$$= 5$
One bag has 5 Black marbles, therefore I have purchased 5 x 5 = 25 Black marbles.
Therefore the price I have paid for Black marbles = 25 x 5 p = 125 p = Rs. 1.25