Multiple choice

A completes a work in 36 days. B and C working together will complete the whole work in how many days if B is 20% more efficient than A and C is 20% less efficient than A. A किसी कार्य को 36 दिनों में समाप्त करता है। B और C मिलकर पूरे कार्य को कितने दिनों में समाप्त करेंगे। यदि B,A से 20% अधिक सक्षम है तथा C,A से 20% कम सक्षम है।

  1. 30 days

  2. 24 days

  3. 18 days

  4. 12 days

  5. None of these इनमें से कोई नहीं

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

A completes in 36 days, so A's rate = 1/36. B is 20% more efficient: rate = 1.2/36 = 1/30 (B completes in 30 days). C is 20% less efficient: rate = 0.8/36 = 1/45 (C completes in 45 days). Combined rate of B and C = 1/30 + 1/45 = 3/90 + 2/90 = 5/90 = 1/18. Option C (18 days) is correct.