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: A can complete the job in 4 hours and B can complete the same job in 3 hours. A works for 1 hour and then B joins and both complete the job. What fraction of the job did B complete

 Option A: 1/7

 Option B: 3/10

 Option C: 1/2

 Option D: 5/6

 Option E: 8/9
Option A

Question: A train speeds past a pole in 15 sec and a platform 140 m long in 25 sec, its length is?

 Option A: 210

 Option B: 150

 Option C: 160

 Option D: 170

 Option E: 180
Option A

Question: A certain manufacturer produces items for which the production costs consist of annual fixed costs totaling $130,000 and variables costs averaging $11 per item. If the manufacturer’s selling price per item is $15, how many items the manufacturer produce and sell to earn an annual profit of $150,000?

 Option A: 2,858

 Option B: 8,667

 Option C: 21,429

 Option D: 35,000

 Option E: 70,000

Option E