Question

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

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

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 for a trolley move across a river, for taking out water form a well and for lifting bricks to a height. However, it is not useful for blind man to cross the road.