What is 2 times one-third plus 3 times one-fourth plus 49 times one-fifth

What is 2 times one-third plus 3 times one-fourth plus 49 times one-fifth

1/2X3+1/3x4+...+1/49x1/50
=(1/2-1/3)+(1/3-1/4)+...+(1/49-1/50)
=1/2-1/50
=12/25