Calculating Malaria Deaths Prevented by Nets

Steps:

• Note total annual deaths: 42,000 in children under 5.
• Nets prevent 50% of malaria cases; assume deaths scale proportionally.
• Compute 50% of 42,000: 21,000 deaths prevented.
• Reduction applies directly to under-5 deaths.

Why B is correct:

• B states the 21,000 deaths prevented, matching the 50% prevention formula applied to total deaths.

Why the others are wrong:

• A: Incorrectly uses 100% prevention, doubling the reduction.
• C: Applies prevention to cases only, ignoring death proportionality.
• D: Not enough information to evaluate without specified value.

Final answer: B