Question

find out the sum of all three digit
number which are divisible by 5​

Answer 1

Step-by-step explanation:

Three digits number divisible by 5 are

100,105,...,995

Here,a=100,d=5,tn=995.

tn=a+(n-1)d

995=100+(n-1)5

(n-1)5=995-100

(n-1)5=885

n-1=885/5

n-1=177

n=177+1

n=178.

S178=178/2[t1+tn]

=89[100+995]

=89×1095.

=97255.

Here is your answer 97255.