Question

FIND THE SUM OF THE A . p 1 +3+5+7--------------- up to 12 tearms

Answer 1

QUESTION :

FIND THE SUM OF THE A.P=> 1 +3+5+7----- up to 12 terms

SOLUTION :

Given : A.P => 1 +3+5+7-----

To find : sum upto 12 terms

Formula used : Sn = n/2[ 2a+(n-1)d]

where :-

• Sn = sum of n terms
• n = number of terms
• a = first term
• d = common difference

Procedure :-

To find the sum of 12terms of given A.P 1+3+5+7----- We will apply the formula :-

$Sn = \frac{n}{2} [ 2a+(n-1)d]$

From the given A.P , we know

• a = 1
• common difference (d) = 3-1 = 2
• n = 12

put these values in the Formula :-

$⟹S12 = \frac{12}{2} [ (2 \times 1)+(12-1)2]$

$⟹S12 = 6 [ 2+(11)2]$

$⟹S12 = 6 [ 2+22]$

$⟹S12 = 6 \times 24$

$⟹S12 = 144$

ANSWER :

Sum of 12 terms of given AP = 144

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Learn more about A.P =>

1. Tn = a+(n-1)d

2. Sn = n/2[2a+(n-1)d]

3. Sn = n/2(a+l)

4. common difference (d) = second term - first term

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