CAT Quantitative Aptitude Questions | CAT Time and Work questions

The question is from Time and Work: Mining. A classic Time and Work Question!! What happens when things do not go as planned?

Question 18: A mining team made a plan to mine up to 300 m in a certain number of days. After working as per plan for 5 days, they added new members to the team and hence could mine 5 m more per day. In this way, 4 days before the planned date, they had mined 295 m. How many meters of mining was initially planned for each day?

1. 30 m
2. 12.5 m
3. 15 m
4. 7.5 m

Explanatory Answer

Method of solving this CAT Question from Pipes Cisterns and Work Time: We can do the trial and error.

Given, 295 m was mined out of which first 5 days – planned. Using option analysis:
a) 30 * 5 + (30 + 5) * (\\frac{300}{30}\\) – 5 – 4) = 150 + 35 * 1 = 185 ≠ 295
b) 12.5 * 5 + 17.5 * (\\frac{300}{12.5}\\) – 5 – 4) = 62.5 + 17.5 * 15 = 325 ≠ 295
c) 15 * 5 + 20 * (\\frac{300}{15}\\) – 5 – 4)1 = 75 + 20 * 11 = 295

The question is "How many meters of mining was initially planned for each day?"

Hence, the answer is "15 m".

Choice C is the correct answer.