A is 150% of B and B is 40% of C. If A + B + C = 20, then the value of 2B + 3C - 4A is equal to:

Explanation

Given: A = 150/100 × B B = 40/100 × C Calculation: ⇒ A + B + C = 20 ⇒ 3B/2 + B + 5B/2 = 20 ⇒ 10B/2 = 20 ⇒B=4 ⇒A=6 ⇒ C = 10 ∴ 2B + 3C - 4A = 2 × 4 + 3 × 10 - 4 × 6 = 14 Step 1: Convert the percentage into ratios. Alternate Method A B C 3 : 2 2 : 5 Step 2: Equalize all three ratios. A B C 3 : 2 2 2 2 : 5 _____________ 6 : 4 : 10 _____________ 3 : 2 : 5 _____________ Given, A + B + C = 20 3 + 2 + 5 units --------- 20 10 units -------- 20 1 unit ------2 ∴ A = 3 × 2 = 6, B = 2 × 2 = 4, C = 5 × 2 = 10 ∴2B + 3C - 4A = 2 × 4 + 3 × 10 - 4 × 6 = 14