Correct Answer - Option 3 : 70%
Given:
An alloy weighing 2100gm contains lead and tin.
Weight of tin in the alloy is 630gm.
Calculation:
Percentage of tin in the alloy = 630/2100 × 100
⇒ Percentage of tin in the alloy = 30%
Percentage of lead in the alloy = 100% - 30% = 70%
∴ Percentage of lead in the alloy is 70%