Multiple choice

Ayushi and Aanchal together can do a work in 12 days. Aanchal and Vaishnavi together do it in 15 days. If Ayushi's efficiency is twice that of Vaishnavi, then the days required for Aanchal alone to finish the work is आयुषी और आँचल एकसाथ मिलकर एक कार्य को 12 दिनों में कर सकती हैं | आँचल और वैष्णवी एकसाथ मिलकर इसे 15 दिनों में कर सकती हैं | यदि आयुषी की कार्यक्षमता वैष्णवी की दोगुनी हो, तो आँचल द्वारा अकेले कार्य को समाप्त करने में आवश्यक दिनों की संख्या है

  1. 60

  2. 20

  3. 15

  4. 25

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

Let total work = LCM(12,15) = 60 units. Ayushi + Aanchal = 5 units/day, Aanchal + Vaishnavi = 4 units/day. Since Ayushi's efficiency is twice Vaishnavi's, let Vaishnavi = x, then Ayushi = 2x. From second equation: Aanchal = 4 - x. Substitute in first: 2x + (4 - x) = 5, so x = 1. Therefore Vaishnavi = 1 unit/day, Ayushi = 2 units/day, and Aanchal = 3 units/day. Aanchal alone takes 60/3 = 20 days.