Multiple choice

An alloy contains zinc, copper and Iron in the ratio 4 : 3 : 2. If 20 kg of copper is added to 90 kg of this alloy, what will be the ratio of zinc and copper in the alloy?

  1. 1 : 1

  2. 1 : 2

  3. 4 : 5

  4. 5 : 4

  5. 3 : 5
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Original alloy: 90 kg total, ratio 4:3:2. Sum of parts = 4+3+2 = 9. Zinc = (4/9)*90 = 40 kg. Copper = (3/9)*90 = 30 kg. Iron = (2/9)*90 = 20 kg. Add 20 kg copper: New Copper = 30 + 20 = 50 kg. Zinc remains 40 kg. Ratio of Zinc to Copper = 40:50 = 4:5.

AI explanation

The original 90 kg alloy contains nine total parts, meaning each part represents 10 kg. The alloy contains 4 parts zinc (40 kg), 3 parts copper (30 kg), and 2 parts iron (20 kg). Adding 20 kg of copper increases the copper amount to 50 kg. The ratio of zinc to copper becomes 40 to 50, which simplifies to 4 to 5.

Keep practicing — related questions