Mathematics
Find the nth term of the A.P. 5, 11, 17, 23,……. Using it, find its
(i) 11th term
(ii) 21st term.
AP
1 Like
Answer
Given,
a = 5
d = 11 - 5 = 6
nth term of an A.P. is given by,
an = a + (n - 1)d
an = 5 + (n - 1)6
= 5 + 6n - 6
= 6n - 1.
(i) 11th term:
⇒ a11 = 5 + (11 - 1)6
= 5 + 10(6)
= 5 + 60
= 65.
(ii) 21st term
⇒ a21 = 5 + (21 - 1)6
= 5 + (20)6
= 5 + 120
= 125.
Hence, nth term = 6n - 1, 11th term = 65 and 21st term = 125.
Answered By
2 Likes
Related Questions
Show that the progression 6, ,……..is an A.P. Write down its
(i) first term
(ii) common difference
(iii) 17th term.
Show that the progression 6, ,……..is an A.P. Write down its
(i) first term
(ii) common difference
(iii) 9th term.
Find the nth term of the A.P. 13, 7, 1, -5, -11, ……. Using it, find its
(i) 9th term
(ii) 16th term.
How many terms are there in the A.P. 6, 10, 14, 18, …., 174 ?