Multiple choice general knowledge math & puzzles

4 men and 6 women can complete a work in 8 days, while 3 men and 7 women can complete it in 10 days. In how many days will 10 women complete it?

  1. 45

  2. 35

  3. 50

  4. 40

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

Let m = one man's daily work, w = one woman's daily work. Then 4m + 6w = 1/8 and 3m + 7w = 1/10. Solving: multiply first by 3 (12m + 18w = 3/8), second by 4 (12m + 28w = 2/5). Subtract: 10w = 2/5 - 3/8 = 1/40. So 10 women complete 1/40 daily, taking 40 days total.