Multiple choice

A, B and C complete a work in 3 days. A alone can do it in 8 days. B alone can also do the same work in 8 days. Which of the following options is true as per the given condition?

  1. C alone can finish the same work in 15 days.

  2. C alone can finish the same work in 8 days.

  3. A and C can finish the same work together in 4 days.

  4. None of the above

  5. e
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A and B together work at 1/8 + 1/8 = 1/4 of the job per day. Since all three complete the job at 1/3 per day, C's rate is 1/3 - 1/4 = 1/12, so C alone takes 12 days. None of the listed statements is true.

AI explanation

Assume the total work is 24 units (the least common multiple of 3 and 8), making the combined daily work of A, B, and C equal to 8 units. Since A and B each take 8 days alone, their individual daily work is 3 units each, meaning C's daily work is 2 units (8 minus 3 minus 3). Therefore, C alone takes 12 days (24 divided by 2), A and C together take 24/5 days, and none of the stated conditions match these results.

Keep practicing — related questions