If you don't want to add them one by one, you can use the formula for the sum of an arithmetic series.
4,8,12,16,20
The multiples of 4 up to 200 are 4, 8, 12, 16, 20 and just keep adding 4 until you get to 200.
There are none.
Their sum is 1200.
24
2
25,20,5,30
Sum of first 25 multiples of 44+8+12....100taking 4 common4(1+2+3+4....+25) = 4*325 =1300
Those are the even numbers: 2, 4, 6, 8, 10 and so on.
204
100, 200, 300 and so on.