Two conveyor belts deliver baggage at constant rates. Belt 1 delivers 3 tonnes in 5 minutes; Belt 2 delivers 1 tonne in 2 minutes. If both belts run together, how long will it take to deliver 33 tonnes?

Introduction / Context:When two sources deliver together, their rates add. Convert both to tonnes per minute, add them, and divide the target tonnage by the combined rate.

Given Data / Assumptions:

• Belt 1: 3 t in 5 min ⇒ 0.6 t/min.
• Belt 2: 1 t in 2 min ⇒ 0.5 t/min.
• Total required = 33 t.

Concept / Approach:Combined rate r = 0.6 + 0.5 = 1.1 t/min. Time = quantity / rate.

Step-by-Step Solution:

Verification / Alternative check:In 30 minutes, they deliver 30 * 1.1 = 33 t, exactly matching the target.

Why Other Options Are Wrong:25:30, 35, 40:45, 28 min do not yield exactly 33 t with the given rates.

Common Pitfalls:Using minutes per tonne (instead of tonnes per minute) and mis-inverting the result; rounding mid-calculation.

Final Answer:30 min