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: Bat is bought for Rs.400 and sold at a gain of 20% find its selling price?

 Option A: Rs.320

 Option B: Rs.350

 Option C: Rs.370

 Option D: Rs.480

 Option E: None of these
[EX A]: Option D

[EX Q]: Question: The average expenditure of a labourer for 6 months was 90 and he fell into debt. In the next 4 months by reducing his monthly expenses to 60 he not only cleared off his debt but also saved 30. His monthly income i

 Option A: 70

 Option B: 72

 Option C: 75

 Option D: 78

 Option E: 81
[EX A]: Option E

[EX Q]: Question: If (A+B) = 4, (B+C) = 9 and (C+D) = 3, what is the value of (A+D)?

 Option A: 16.

 Option B: 8.

 Option C: 7

 Option D: 2.

 Option E: -2
[EX A]:
Option E