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.

[EX Q]: Question: If a college has 15 staff for every 700 students, then what is the number of staff for 1400 students?

 Option A: 30

 Option B: 14

 Option C: 12

 Option D: 17

 Option E: 19
[EX A]: Option A

[EX Q]: Question: The average salary per head of the entire staff of an office including the officers and clerks is Rs.90. The average salary of officers is Rs.500 and that of the clerks is Rs.84. If the number of officers is 2, find the number of officers in the office?

 Option A: 620

 Option B: 720

 Option C: 820

 Option D: 920

 Option E: 1020
[EX A]: Option C

[EX Q]: Question: The average weight of A,B,C is 45 Kg. The avg wgt of A & B be 40Kg & that of B,C be 43Kg. Find the wgt of B.

 Option A: 36kg

 Option B: 84kg

 Option C: 31kg

 Option D: 45kg

 Option E: 12kg
[EX A]:
Option B