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: 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: A bus takes 3 hours to cover a distance of 500 Km. how much should the speed in Kmph be maintained to cover the same direction in 5/3th of the previous time?

 Option A: 75 Kmph

 Option B: 100 Kmph

 Option C: 90 Kmph

 Option D: 65 Kmph

 Option E: 70 Kmph
[EX A]: Option B

[EX Q]: Question: By selling an article at Rs.800, a shopkeeper makes a profit of 25%. At what price should he sell the article so as to make a loss of 40%?

 Option A: 228

 Option B: 384

 Option C: 267

 Option D: 288

 Option E: 276
[EX A]:
Option B