A work-force of 420 men with a contractor can finish a certain piece of work in 9 months. How many extra men must he employ to complete the job in 7 months?

A work force of 50 men with a contractor can finish a piece of work in 5 months. In how many months the same work can be completed by 125 men?

A work force of 50 men with a contractor can finish a piece of work in 5 months. In how many months the same work can be completed by 125 men?

An employer has a workforce of 300 employees to finish a project in 8 months.How many extra employees should he employ to complete the project in 6 months?

8 men can finish a piece of work in 15 hours.In how many hours can 20 men finish it?

If 36 men can finish a piece of work in 35 days.how many days will 15 men take to do it ?

A contractor undertook a contract to complete a part of a stadium in 9 months with a team of 560 persons. Later on, it was required to complete the job in 5 months. How many extra persons should he employ to complete the work?