A box contains Rs. 56 in the form of coins of 1 rupee, 50 paise and 25 paise. The number of 50 paise coins is double the numbers of 25 paise coins and four times the number of one rupee coins. How many 50 paise coins are there in the box?

Answer: Option B

Total Amount = Rs. 56
Number of coins Ratio of 50 paise coin and 25 paise coins = 2 : 1
Number of coins Ratio of Rs. 1 coin and 50 paise coins = 1 : 4
∴ Number of coins Ratio of Rs. 1 : 50 paise : 25 paise = 1 : 4 : 2

Ratio of coin's value
Rs. 1 : 50 paise : 25 paise (value) = 1 : 2 : 0.50
(Multiply by 2 to remove the fraction value in above ratio)
i.e Rs. 1 : 50 paise : 25 paise (value) = 2 : 4 : 1
Value of 50 paise coin in Rs. 56 = $$\frac{4}{7}\times 56=32$$
Number of 50 paise coin is = 32 × 2 = 64