Math, asked by preet1731, 1 year ago

how many numbers between 400 to 700 are divisible by 9 or 11 (exclusively)

Answers

Answered by mysticd
8
Hi ,

i ) 405 ,414 , ...., 693 are numbers between

400 to 700 divisible by 9

This is clearly in A.P.

first term ( a ) = 405

common difference ( d ) = a2 - a1

d = 414 - 405 = 9

let number of terms = n

an = 693

a + ( n - 1 )d = 693

405 + ( n - 1 )9 = 693

divide each term with 9 , we get

45 + n - 1 = 77

n = 77 - 44

n = 33

ii ) 407 ,418 ,.... , 693 are numbers

between 400 to 700 divisible by 11.

It is clearly in A.P.

first term ( a ) = 407

common difference ( d ) = 11

an = 693

a + ( n - 1 )d = 693

407 + ( n - 1 ) 11 = 693

divide each term with 11 , we get

37 + n - 1 = 63

n = 63 - 36

n = 27

I hope this helps you.

: )
Answered by maryamkincsem
5

The numbers divisible by 9:

Ranging from 400-700

405, 414, 423, 432,441, 423, 432, ....... There are a total of 32 numbers from 400-700 which are divisible by the number 9.

This question is that of AP( Arithmetic Progression)

( a ) = 405, i.e. the 1st term

( d ) = a2 - a1 i.e. common difference

step 1:

Finding the d = 414 - 405 = 9

next step is that of finding the concerned term

let number of terms = n

If; (a)(n) = 693

a + ( n - 1 )(d) = 693 (693 being the last number which can be divisible, in the entire list)

405 + ( n - 1 )(9) = 693


45 + n - 1 = 77

n = 77 - 44

n = 33

Thanks for asking. I hope you like the answer and it helps you out.

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