A man walks 1 km. on 1st day, 2 km. on 2nd day, 3 km. on

A man walks 1 km. on 1st day, 2 km. on 2nd day, 3 km. on 3rd day and so on. The total distance the man covers in 10 days is :

According to the question,
Required distance = (1 + 2 + 3 + ---- + 10) km.
We know that ,

	Sum = 1 + 2 + 3 + .........+ n =	n(n + 1)
		2

Here , n = 10

Required distance =	10 × 11	= 55 km
	2