Pls help me out...

1 ) The sum of all natural numbers from 100 to 300 which are divisible by 4 or 5??

2)  If  x = 1 + 1/3 + 1/3² +.............∞

    y = 1 + 1/4 + 1/ 4² +............∞     Find xy

a)2

b)1

c)8/9

d)1/2

pls solve this....

thanks in advance..