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If 11 AM's are inserted between 28 and 1...

If 11 AM's are inserted between 28 and 10, the number of integral AM's is

A

5

B

6

C

7

D

8

Text Solution

Verified by Experts

The correct Answer is:
A
Let 11AM's are `A_(1),A_(2),A_(3),"….."A_(11)`.
Given, `28,A_(1),A_(2),A_(3),"….."A_(11)`,10 are in AP.
`:.d=(10-28)/(12)=-(3)/(2)`
`:.A_(i)=28+id=28-(3)/(2)i`
It is clear that `A_(2),A_(4),A_(6),A_(8),A_(10)` are integral AM's.
Hemce, number of integral AM's are 5.
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