Final answer:
To find the number of 50 paise coins, use the given ratio and total value equation to solve for x and then multiply the value of 50 paise coins by 4x. The number of 50 paise coins is 80. Option B is correct.
Step-by-step explanation:
To find the number of 50 paise coins, we need to determine the ratio of 50 paise coins to the total value of coins in the bag.
Given that the ratio of 1 rupee coins, 50 paise coins, and 10 paise coins is 3:4:5, we can calculate the value of each type of coin using this ratio.
Let's assume that there are 3x 1 rupee coins, 4x 50 paise coins, and 5x 10 paise coins. The value of 1 rupee coin is 1x, the value of 50 paise coin is 0.50x, and the value of 10 paise coin is 0.10x.
Therefore, the total value of all the coins is 3x + 0.50x + 0.10x = 187. Solving this equation, we get x = 20.
Since there are 4x 50 paise coins, the number of 50 paise coins is 4 * 20 = 80. Therefore, the correct answer is option b) 80.