Question
A bag contains 10-paisa, 20-paisa and 50-paisa coins in
the ratio of 8:9:10, respectively. If the total amount in the bag is Rs. 38, then find 80% of the number of 20-paisa coins in the bag.Solution
Let number of 10 paisa, 20 paisa and 50 paisa coins be β8xβ, β9xβ and β10xβ, respectively. ATQ, (0.1 Γ 8x) + (0.2 Γ 9x) + (0.5 Γ 10x) = 38 Or, 0.8x + 1.8x + 5x = 38 Or, 7.6x = 38 So, x = 5 So, number of 20 paisa coins = 9x = 45 Therefore, required number of coins = 0.8 Γ 45 = 36
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