Given:
A man walks for x hours at a speed of (x + 1) km/h and cycles for (x - 1) hours at a speed of (2x + 5) km/h.
Total distance travelled is 90 km.
To find:
The value of x.
Solution:
We know that,
A man walks for x hours at a speed of (x + 1) km/h, so walking distance is
km
The man cycles for (x - 1) hours at a speed of (2x + 5) km/h, so the cycling distance is
km
Now,
Total distance = 90 km
Time cannot be negative. So, the only possible value of x is 5.