Question

In which of the following cases, a pulley cannot be used?

• A. Lifting bricks to a height.
• B. Helping a blind man cross the road.
• C. Taking out water form a well.
• D. Helping a trolley move across a river.

Answer 1

The correct option is B Helping a blind man cross the road.

Pulley is a small wheel with a rope or chain that is used to lift something up. Pulleys are useful to move a trolley across a river. It is also used to draw water form a well. Workers use pulley to lift bricks to a height.
However, it is not useful for blind man to cross the road.