CAT Quantitative Aptitude Questions | CAT Time and Work questions

The question is from Time and work: Watering the garden. A simple question and with a small subtraction we can arrive at the answer.

Question 19: Ajay and Suraj can water a garden in 45 minutes and 40 minutes respectively. They started working together but after some time Ajay left to watch a cricket match. Suraj hurriedly finished the work in next 23 minutes and joined Ajay. After how many minutes had Ajay left?

1. 9 min
2. 8 min
3. 7 min
4. 10 min

Explanatory Answer

Method of solving this CAT Question from Pipes Cisterns and Work Time: What fraction of work done by both of them together?

Suraj took 23 minutes to finish the remaining work = \\frac{23}{40}\\)
Work finished by Ajay and Suraj together = \\frac{17}{40}\\)
Time taken = \\frac{17/40}{(1/45)+(1/40)}\\)= \\frac{17}{8/9 + 1}\\) = \\frac{17}{17/9}\\) = 9 mins

The question is "how many minutes had Ajay left?"

Hence, the answer is "9 min".

Choice A is the correct answer.