You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.

Question: In a company 200 persons, working 6 hours per day complete 1/3 rd of the work in 7 days. Employee number of additional persons, working 4 hrs per day, required to complete the remaining work in 15 days is :

 Option A: 60

 Option B: 80

 Option C: 90

 Option D: 70

 Option E: 50
Option B

Question: Running at the same constant rate, 8 identical machines can produce a total of 240 pens per minute. At this rate, how many pens could 5 such machines produce in 5 minutes?

 Option A:  114

 Option B:  108

 Option C:  192

 Option D:  750

 Option E:  777
Option D

Question: The average age of 40 students in a class is 10years. If teacher's age is also included then average increases 1year then find the teacher's age?

 Option A: 59

 Option B: 55

 Option C: 61

 Option D: 51

 Option E: 36

Option D