Multiple choice

Quantity I: Working alone, B can complete the work in 20 days. C is twice as efficient as B and A takes 2 days more than it takes C to complete the work. Working together, in how much time would they be able to complete 7 such works? Quantity II: Working alone, A, B and C can do a work in 24, 30 and 40 days respectively. How long will it take them to complete the work if only A and B work for the first 6 days and then C started the work? मात्रा I: अकेले कार्य करते हुए, B 20 दिनों में कार्य पूरा कर सकता है। C, B से दोगुना कुशल है और A को कार्य को पूरा करने में C से 2 दिन अधिक समय लगता है। एक साथ काम करते हुए, वे ऐसे 7 कार्यों को कितने समय में पूरा कर पाएंगे? मात्रा II: अकेले कार्य करते हुए, A, B और C क्रमशः 24, 30 और 40 दिनों में कार्य कर सकते हैं। यदि A और B पहले 6 दिनों के लिए काम करते हैं और फिर C कार्य करता है तो उन्हें काम पूरा करने में कितना समय लगेगा?

  1. Quantity I > Quantity II मात्रा I > मात्रा II

  2. Quantity I ≥ Quantity II मात्रा I ≥ मात्रा II

  3. Quantity I < Quantity II मात्रा I < मात्रा II

  4. Quantity I ≤ Quantity II मात्रा I ≤ मात्रा II

  5. Quantity I = Quantity II or relation can’t be established मात्रा I = मात्रा II या सम्बन्ध स्थापित नही किया जा सकता|
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

QI: B takes 20 days alone. C is twice efficient, so C takes 20/2 = 10 days. A takes 10+2 = 12 days. Together: 1/12 + 1/20 + 1/10 = 5/60 + 3/60 + 6/60 = 14/60 = 7/30 work/day. For 7 works: Time = 7 × 30/7 = 30 days. QII: A(24), B(30), C(40). A+B work for 6 days: 6×(1/24+1/30) = 6×(5/120+4/120) = 6×9/120 = 54/120 = 9/20 work. Remaining = 11/20. Then A+B+C together: 1/24+1/30+1/40 = 5/120+4/120+3/120 = 12/120 = 1/10. Time for remaining = (11/20) / (1/10) = 11/2 = 5.5 days. Total = 6 + 5.5 = 11.5 days. Comparing: QI = 30 days, QII = 11.5 days. QI > QII, so A is correct.

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