Question

Q1.first term and common difference of ana.p are 6and3 respectively find 27​

Answer 1

Explanation:

Given

we have given first term (a) = 6

common difference (d) = 3

To Find

We have to find 27th term of an ap

SOLUTION:

Formula used here :

aₙ= a+(n-1)d

27th term can be written as

a₂₇= a+(27-1)d

a₂₇= a+26d

Now,put the values :

a= 6 & d = 3

a₂₇= a+26d

a₂₇= 6+26(3)

a₂₇= 6+78

a₂₇= 84

hence ,27th term is 84.

Extra information=>

If a,a₂,a₃,a₄,are in ap

then find sum

sₙ=n/2(2a+(n-1)d

If a,a₂,a₃,a₄,are in ap

then find the common difference

d= second term(a₂) -first term(a)

Answer 2

$\large\underline\mathfrak\red{Given \: :- }$

• a = 6
• d = 3

$\large\underline\mathfrak\red{To \: find \: :- }$

• S27

$\large\underline\mathfrak\red{Solution \: :- }$

$\large\underline\mathfrak\green{Using \: formula \: :- }$

$\boxed{\bf S_27 = \frac{n}{2} (2a + (n - 1)d)}$

Required answer

$\sf\implies{ \frac{27}{2}(2 \times 6 + 26 \times 3) } \\ \sf\implies{ \frac{27}{2} (12 + 78)} \: \: \: \: \: \: \: \: \: \: \: \: \: \\ \sf\implies{ \frac{27}{2} (90) = 1215 \: \: \: \: \: \: \: }$

$\boxed{\bf S27 = 1215}$