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.

[Q]: Question: The average age of 15 students of a class is 15 years. Out of these, the average age of 4 students is 14 years and that of the other 10 students is 16 years, The age of the 15th student is

 Option A: 11

 Option B: 12

 Option C: 9

 Option D: 14

 Option E: 15
[A]: Option C


[Q]: Question: Two alloys A and B are composed of two basic elements. The ratios of the compositions of the two basic elements in the two alloys are 5 : 3 and 1 : 2, respectively. A new alloy X is formed by mixing the two alloys A and B in the ratio 4 : 3. What is the ratio of the composition of the two basic elements in alloy X ?

 Option A: 1 : 1

 Option B: 2 : 3

 Option C: 5 : 2

 Option D: 4 : 3

 Option E: 7 : 9
[A]: Option A


[Q]: Question: In a race of length L metres, Johnson beats Lewis by P metres and Greene by Q metres, By how many metres does Lewis beat Greene in the same race ? (P<Q)

 Option A: L(L-Q

 Option B: L(Q-P

 Option C: L-Q

 Option D: P-Q

 Option E: P+Q
[A]:
Option B