Mathematics is a vast field, and difficulty can be subjective. However, here are 10 challenging math questions along with their answers:

1. Question: What is the value of π^2?
   Answer: π^2 is approximately equal to 9.8696.

2. Question: Solve the equation: 3x + 5 = 2x + 10.
   Answer: By subtracting 2x and 5 from both sides, we find x = 5.

3. Question: What is the sum of the first 100 positive odd numbers?
   Answer: The sum of the first n positive odd numbers is given by n^2. Thus, the sum of the first 100 odd numbers is 100^2 = 10,000.

4. Question: What is the probability of rolling two dice and getting a sum of 7?
   Answer: There are six possible outcomes that sum up to 7 (1+6, 2+5, 3+4, 4+3, 5+2, 6+1). As there are 36 possible outcomes in total when rolling two dice, the probability is 6/36 = 1/6.

5. Question: If a car travels at a speed of 60 miles per hour, how many feet does it travel in one second?
   Answer: There are 5280 feet in a mile and 3600 seconds in an hour. Thus, the car travels 60 * 5280 / 3600 = 88 feet in one second.

6. Question: What is the square root of -1?
   Answer: The square root of -1 is denoted by the imaginary unit i.

7. Question: Solve the equation: log2(x) + log2(x – 2) = 3.
   Answer: By applying logarithmic properties, the equation simplifies to log2(x(x – 2)) = 3. Converting to exponential form, we get x(x – 2) = 2^3, which becomes x^2 – 2x – 8 = 0. Solving the quadratic equation, we find x = -2 or x = 4. However, since log2 of a negative number is undefined, the only valid solution is x = 4.

8. Question: If a train travels at a speed of 80 kilometers per hour, how many meters does it travel in 2 minutes?
   Answer: There are 1000 meters in a kilometer and 60 seconds in a minute. Thus, the train travels 80 * 1000 * (2/60) = 2666.67 meters in 2 minutes.

9. Question: What is the value of 2 to the power of 100?
   Answer: 2^100 is a large number, equal to 1,267,650,600,228,229,401,496,703,205,376.

10. Question: Solve the equation: e^x + 2 = 5.
    Answer: By subtracting 2 from both sides and taking the natural logarithm of both sides, we find x = ln(3).