The statement that the mechanical advantage of a machine is 3 means that the

Analyze the question: We are asked what it means when a machine has a mechanical advantage (M.A.) of 3.

Concept: Mechanical advantage is the ratio of the load to the effort:

M.A. = Load / Effort

Velocity ratio (V.R.) is the ratio of the distance moved by the effort to the distance moved by the load. Efficiency = M.A. / V.R. × 100%.

Solution: If M.A. = 3, then

Load / Effort = 3, so Load = 3 × Effort.

This means the load is three times the effort. Equivalently, Effort : Load = 1 : 3.

Checking each option:

• A. Efficiency = M.A./V.R. × 100%. We don't know V.R., so we can't say the efficiency is 33⅓%. Wrong.
• B. This says effort is 3 times the load, which is the reverse of the true relationship. Wrong.
• C. M.A. is not generally 3 times the V.R. In fact, M.A. ≤ V.R. for a real machine. Wrong.
• D. Effort : Load = 1 : 3. This matches Load = 3 × Effort. Correct.
• E. V.R. is not necessarily 3. Only for an ideal (100% efficient) machine would V.R. equal M.A. Wrong.

Answer: The ratio of the effort to the load is 1 : 3, which is option D.

Tip: Remember M.A. = Load ÷ Effort. Think "M.A. tells how many times the machine multiplies your effort." An M.A. of 3 means a small effort lifts a load 3 times bigger, so Effort : Load = 1 : 3. Don't confuse M.A. with V.R., which is about distances, not forces.