Multiple choice

Some persons can do a work in 30 days. If there were 5 more persons the work would have been completed in before 10 days. How many persons were there at the starting ?

  1. 10

  2. 15

  3. 20

  4. 25

  5. 28

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let n persons complete work in 30 days. With n+5 persons, work completes in 30-10 = 20 days. Total work = n × 30 = (n+5) × 20. Solving: 30n = 20n + 100, so 10n = 100, giving n = 10 persons.