Multiple choice

A takes 80% of the time taken by B to complete a work and B takes 75% of the time taken by C. They began the work together but C left 4 days before completion of the work. In how many days was the work done, if A takes 24 days to complete the work? A एक कार्य को पूरा करने के लिए B द्वारा लिए गये समय का 80% समय लेता है और B उसी कार्य को पूरा करने के लिए C द्वारा लिए समय का 75% समय लेता है यदि वे एकसाथ कार्य करना प्रारम्भ करते है परन्तु B कार्य समाप्त होने के 4 दिन पहले कार्य छोड़कर चला जाता है। कितने दिनों में कार्य पूरा हुआ यदि A कार्य को पूरा करने में 24 दिन लेता है?

  1. 13

  2. 12

  3. 14

  4. 11

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

A takes 24 days. Since A = 80% of B's time, B = 24/0.8 = 30 days. Since B = 75% of C's time, C = 30/0.75 = 40 days. Rates: A = 1/24, B = 1/30, C = 1/40. C leaves 4 days early, so A and B work for d days, C works for (d-4) days. Work equation: d/24 + d/30 + (d-4)/40 = 1. Solving with LCM 120: 5d + 4d + 3(d-4) = 120, giving 12d = 132, so d = 11 days. Option D matches. Note: English text (C left) is correct; Hindi text incorrectly mentions B left.