Multiple choice

Dev and Tukku can do a piece of work in 45 and 40 days respectively. They began the work together, but Dev leaves after some days and Tukku finished the remaining work in 23 days. After how many days did Dev leave?

  1. 7 days

  2. 8 days

  3. 9 days

  4. 11 days
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let Dev work for x days. Dev's daily work is 1/45, Tukku's is 1/40. Tukku worked for (x + 23) days total. The equation is x/45 + (x + 23)/40 = 1. Multiplying by 360 gives 8x + 9(x + 23) = 360, so 17x + 207 = 360, 17x = 153, x = 9.

AI explanation

Using the Least Common Multiple method, assume the total work is 360 units, making the daily work units of Dev and Tukku equal to 8 and 9 respectively. Tukku works alone for 23 days to complete 207 units, meaning 153 units were completed when they worked together. Their combined daily work is 17 units, so they worked together for 153 / 17 = 9 days.

Keep practicing — related questions