Q&A - Ask Doubts and Get Answers
Q

How many three-digit numbers are divisible by 7?

Q : 13       How many three-digit numbers are divisible by \small 7?
 

Answers (1)
Views

We know that the first three digit number divisible by 7 is 105 and last   three digit number divisible by 7 is 994
Therefore,
a = 105 , d = 7 \ and \ a_n = 994
Let there are n three digit numbers divisible by 7
Now, we know that
a_n = a+ (n-1)d
\Rightarrow 994 = 105 + (n-1)7
\Rightarrow 7n = 896
\Rightarrow n = \frac{896}{7} = 128
Therefore,  there are 128 three digit numbers divisible by 7

Exams
Articles
Questions