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 certain sum earns simple interest of Rs. 800 in 2 years at a certain rate of interest. If the same sum earns compound interest of Rs.900in the same period of 2 years, What must be the rate of interest?

 Option A: 25%

 Option B: 10%

 Option C: 15%

 Option D: 20%

 Option E: 30%
Option A

Question: A and B’s salaries together amount to Rs. 2,000. A spends 95% of his salary and B spends 85% of his. If now their savings are the same, what is A’s salary?

 Option A: 0998

 Option B: 2899

 Option C: 1889

 Option D: 1500

 Option E: 2881
Option D

Question: If 30% of 100 is greater than 50% of a number by 10, then the number is?

 Option A: 40

 Option B: 30

 Option C: 60

 Option D: 80

 Option E: 50

Option A