Question

find the sum of all integers from 1 to 500 which are multiples of 2 or 5

Answer 1

Answer:

The numbers which are multiple of 2 as well as 5 are also multiple of 10.So, they form an arithmetic progression starting with 10 and common difference of the progression is 10.

Here,number of the terms of A.P. from 1 to 500 is =(500–10)/10+1=50

So,sum=50*(2*10+(50–1)*10)/2=12750

Step-by-step explanation:

Answer 2

The numbers which are multiple of 2 as well as 5 are also multiple of 10.So, they form an arithmetic progression starting with 10 and common difference of the progression is 10.

Here,number of the terms of A.P. from 1 to 500 is =(500–10)/10+1=50

So,sum=50*(2*10+(50–1)*10)/2=12750