Question

give a=5,b=3,an=50 find n and fn​

Answer 1

Answer :

$\large{ \star\:\:\boxed{\sf{a\bf{_{16}}\:=\:50}}\:\:\star }$

Correct Question :–

Given is a = 5 , d = 3 and aₙ = 50 . Find the value of n .

Explanation :

Given :–

• 5 , 8 , 11 , ... are in A.P.
• where a = 5 and d = 3

To Find :–

• The value of n .

Formula Applied :–

• $\boxed{\star\:\:\bf{a_n\:=\:a\:+\:(n\:-\:1)d}\:\:\star}$

Solution :–

We have,

• a = 5
• d = 3
• aₙ = 50

Putting these values in the Formula :

$\rightarrow\sf{a_n\:=\:a\:+\:(n\:-\:1)d}$

$\rightarrow\sf{50\:=\:5\:+\:(n\:-\:1)(3)}$

$\rightarrow\sf{50\:-\:5\:=\:(n\:-\:1)(3)}$

$\rightarrow\sf{45\:=\:(n\:-\:1)(3)}$

$\rightarrow\sf{\dfrac{45}{3} \:=\:(n\:-\:1)}$

$\rightarrow\sf{15\:=\:n\:-\:1}$

$\rightarrow\sf{n\:=\:15\:+\:1}$

$\rightarrow\boxed{\bf{n\:=\:16}}$

∴ The 16th Term of this A.P. is 50 .