Multiple choice

Two always contain tin and Iron in the ratio of 1 : 2 and 2 : 3. If the two always are mixed in the proportion of 3 : 4 respectively. (by weight) The ratio of tin and Iron in the newly formed always is-

  1. 21 : 13

  2. 13 : 21

  3. 14 : 21

  4. 21 : 14

  5. None of these

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Alloy 1 (3 units at 1:2): tin = 3 × 1/3 = 1, iron = 3 × 2/3 = 2. Alloy 2 (4 units at 2:3): tin = 4 × 2/5 = 1.6, iron = 4 × 3/5 = 2.4. Combined: tin = 1 + 1.6 = 2.6, iron = 2 + 2.4 = 4.4. Ratio = 2.6 : 4.4 = 13 : 21.