Question

Find the numbers of all three digit natural numbers which are divisible by 7.{this is a question from arethmetic progressions

Answer 1

Answer:

128

Step-by-step explanation:

All three-digit natural numbers which are divisible by 7 are

105,112,119,126,...,994 which are in AP with a=105,d=7,l=994

Let the number of these terms be n. Then,

a

n

=994

a+(n−1)d=994

105+(n−1)×7=994

n=128