`B=1/(2.6)+1/(6.10)+...+1/(96.100)`
`=>4B=4(1/(2.6)+1/(6.10)+...+1/(96.100))`
`=>4B=4/(2.6)+4/(6.10)+...+4/(96.100)`
`=>4B=1/2-1/6+1/6-1/10+...+1/96-1/100`
`=>4B=1/2-1/100`
`=>4B=49/100`
`=>B=49/400`
`C=2/(1.6)+2/(6.11)+....+2/(501.506)`
`=>2,5C=2,5(2/(1.6)+2/(6.11)+....+2/(501.506))`
`=>2,5C=5/(1.6)+5/(6.11)+...+5/(501.506)`
`=>2,5C=1-1/6+1/6-1/11+...+1/101-1/506`
`=>2,5C=1-1/506`
`=>2,5C=505/506`
`=>C=101/253`