A cyclist travels 15 km in the first hour and then increases her speed to 20 km/h for the next hour. What is her average speed over the two hours?
Category: Math · Difficulty: hard
Hint: Average speed is total distance divided by total time.
Answer
17.5 km/h
Explanation
The total distance is 15 km + 20 km = 35 km and total time is 2 hours, giving an average speed of 35/2 = 17.5 km/h.
This is a hard math riddle — a tricky one that takes a little thought. The answer is 17.5 km/h.
More Math riddles
- If I take the average of my eight consecutive numbers, the result is the same as the average of the first…
- What is the sum of the angles in a triangle, and what is the smallest angle if the largest is twice as large…
- A car travels 100 km at a speed of 50 km/h and then returns at 100 km/h. What is the average speed for the…
- Given the function f(x) = 2x^2 - 4x + 1, what is the minimum value of f(x)?
- If you have three test scores: 80, 90, and 100, with weights of 2, 3, and 5 respectively, what is the…
- What is the volume of a sphere with a radius of 3 units? Use π ≈ 3.14.
- In a triangle, the angles can be quite sly. If one angle is twice another, what can you apply?
- Shift me left and I’m ten times more, shift me right, and I’m a tenth for sure. What am I?