Question

Find the middle term of the A,P,5,8,11...,65

Answer 1

Answer:

formula used =

⚫ tn = a+(n-1)d

⚫ middle term=(n+1)/2

EXPLANATION

⚫AP= 5,8,11......,65.

↪a(1st term)

[ a = 5 ]

↪ d (common difference) = n2-n1

= 8 - 5

= 3

[ d = 3]

↪ [ tn(last term) = 65.]

➡NOW,

↪ Total No Of terms are ,

↪ tn = a+(n-1)d

↪65 =5+(n-1)3

↪65-5=3n-3

↪(60+3)/3=n

↪[n=21]

➡therefore middle term ,

= (n+1)/2

=(21+1)/2

= 11th

➡middle term is [11th term]

↪tn = a+(n-1)d

↪ t11th = 5+(11-1) 3

= 5+10x3

= 5+30

= 35

therefor middle term (11th term) is 35 ⚫