If the common difference of an ap is 3 then a20 – a15 is Question If the common difference of an ap is 3 then a20 – a15 is in progress 0 Math Raelynn 1 week 2021-09-14T18:32:16+00:00 2021-09-14T18:32:16+00:00 2 Answers 0 views 0

## Answers ( )

GIVEN:–• Common difference (d) = 3

TOFIND:–ㅤ

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SOLUTION:–ㅤ

• We know that nth term of A.P. if first term is ‘a’ –

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• Now –

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• And –

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• So that –

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Answer:We know that,

an=a+(n-1)d

So,a20=a+(20-1)(3)

a20=a+19(3)

a20=a+57

Similarly, a15=a+14d

a15=a+14(3)

a15=a+42

Now,a20-a15=(a+57)-(a+42)

=a+57-a-42

=57-42

=15