Find the sum of all natural numbers lying between 100 and 1000, which are multiples of 5.

Answer

N/a

Explanation

Natural numbers between 100 and 1000, which are multiples 5 are
105+110+115+…+995 (A.P)
Hera a=105, d=110-105=5
`"Let "T_(n)=995`
`rArr" "105+(n-1)5=995`
`rArr" "n=179`
`"Sum of terms "S_(n)=(n)/(2)(a+l)`
`=(179)/(2)(105+995)`
`=179xx550`
`=98450`