=1/6*(1/1*4-1*4/7)+1/6*(1/4*7-1/7*10)+……+1/6*(1/94*97-1/97*100)
=1/6*(1/1*4-1*4/7+1/4*7-1/7*10+……+1/94*97-1/97*100)
=1/6*(1/1*4-1/97*100)
=101/2425