Question

find the number of integers between 100 and 1000 that are divisible by 7 not divisible by 7​

Answer 1

Answer:

So, 128 numbers between 100 and 1000 are divisible by 7. (b). Now, there are 899 numbers between 100 and 1000. So, 899−128=771 numbers are not divisible by 7 between 100 and 1000.

Answer 2

Question :

Find the number of integers between100 & 1000 that are

i) divisible by 7  

ii) not divisible by 7

Answer:

i) Next number after 100 which is  divisible by 7 is 105 and biggest three digit number divisible by 7 is

1000÷7 has 6 as reminder

∴ 1000–6=994

994=7*142

105=7*15

Therefore between 100 and 1000 there will be

142–15=127 numbers divisible by 7 and considering 105 there are 128 such numbers.  

ii) There are total 889 numbers between 100 and 1000 out of which 128 numbers are divisible by 7

∴ Remaining numbers i.e. 899 - 128 = 771 are not divisible by 7.