Question

find how many three digit natural number are divisible by 5

Answer 1

100,105,…........995,

tital numbers=(995-100)/5 +1,

=895/5 +1,

=179+1=180✓✓✓✓

Answer 2

100,105,110,..........,995Here ,a=100 , an=995 , d=5 and we have to find n.So,an=a+(n-1)d995=100+(n-1)5995-100=(n-1)5895/5=(n-1)179=n-1n=179+1n=180