TASK DEFINITION: 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.
PROBLEM: Question: On a partly cloudy day, Derek decides to walk back from work. When it is sunny, he walks at a speed of s miles/hr (s is an integer) and when it gets cloudy, he increases his speed to (s + 1) miles/hr. If his average speed for the entire distance is 2.8 miles/hr, what fraction Q of the total distance did he cover while the sun was shining on him?

 Option A: 1/4

 Option B: 4/5

 Option C: 1/5

 Option D: 1/6

 Option E: 1/7

SOLUTION: Option E

PROBLEM: Question: John has only pennies, dimes, and nickels in a jar. The jar has at least 1 but no more than 4 pennies. If the jar has at least 1 nickel and 1 dime, which of the following could NOT be the total amount of money in the jar?

 Option A: 54

 Option B: 55

 Option C: 56

 Option D: 57

 Option E: 58

SOLUTION: Option B

PROBLEM: Question: Three grades of milk are 2 percent, 3 percent and 5 percent fat by volume. If x gallons of the 2 percent grade, y gallons of the 3 percent grade, and z gallons of the 5 percent grade are mixed to give x+y+z gallons of a 4 percent grade, what is x in terms of y and z?

 Option A: y + 3z

 Option B: (y +z

 Option C: 2y + 3z

 Option D: z/2

 Option E: 3y + 4.5z

SOLUTION:
Option D