Multiple choice

Three technicians a, b and c have to make a server. a and b can make a server in 12 hours, b and c can destroy that server in 15 hours, and c and a can make the server in 20 hours. In how many days will the server be ready to work, if the work starts with a and all work simultaneously?

  1. 5/12 days

  2. 10 hours

  3. 30 days

  4. 5/4 days

  5. 15/4 days
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

in three days, 2 unit of total work = lcm of time = 60 unit So, time taken = 60/2 * 3 = 90 hours This answer is correct.

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