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 375*s is a perfect square then s can be which of the following numbers?

 Option A: 21

 Option B: 35

 Option C: 54

 Option D: 15

 Option E: 150
[EX A]: Option D

[EX Q]: Question: Three numbers are in the ratio 5 : 6 : 7. The sum of its longest and smallest numbers equals the sum of the third number and 54. Find the third number?

 Option A: A

 Option B: B

 Option C: C

 Option D: D

 Option E: E
[EX A]: Option E

[EX Q]: Question: workers decided to raise Rs.3 lacs by equal contribution from each. Had they contributed Rs.50 eachextra, the contribution would have been Rs.3.50 lacs . How many workers were they?

 Option A: 220

 Option B: 230

 Option C: 500

 Option D: 560

 Option E: 1000
[EX A]:
Option E