Multiple choice

30 men can do a work in X days and 25 women can do same work in (X+9) days. If the amount of work done by 36 men in 3 days is equal to the work done by 90 women in 2 days. Find in how many days 15 men and 5 women can do the work? 30 पुरुष एक कार्य को X दिनों में कर सकते हैं और 25 महिलाएं उसी कार्य को (X+9) दिनों में पूरा कर सकती हैं। यदि 36 पुरुषों द्वारा 3 दिन में किया गया कार्य और 90 माहिलाओं द्वारा 2 दिन में किया गया कार्य बराबर है, तो 15 पुरुष और 5 महिलायें कार्य को कितने दिनों में कर सकते हैं?

  1. 17 days/दिन

  2. 18 days/दिन

  3. 15 days/दिन

  4. 12 days/दिन

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

Let m = man's work per day, w = woman's work per day. From 36 men in 3 days = 90 women in 2 days: 108m = 180w, so m = 5w/3. From 30 men in X days = 25 women in (X+9) days: 30mX = 25w(X+9). Substituting m: 30(5w/3)X = 25w(X+9), giving 50X = 25(X+9), so X = 9. Combined work of 15 men + 5 women per day = 15(5w/3) + 5w = 30w. Total work = 25w(18) = 450w. Days needed = 450w/30w = 15. The answer is 15 days.