The 11th term and the 21st term of an A.P. are 16 and 29 respectively, then find the 41th term of that A.P.
Answers
ANSWER :–
41 th term = 55
EXPLANATION :–
GIVEN :–
• 11 th term of A.P. = 16
• 21 th term of A.P. = 29
TO FIND :–
41 th term
SOLUTION :–
● 11 th term of A.P. = a + 10d = 16 ------(1)
● 21 th term of A.P. = a + 20d = 29 -------(2)
➪ Here , a = first term
d = common difference
⮕ by equation (1) and (2) –
=> 10d = 13
=> d = 13/10
• Now put the value of 'd' in equation (1) –
=> a = 3
⮕ Now , 41 th term = a + 40d
=> 41th term = 3 + 40 (13/10)
=> 41th term = 55
__________________________
- The 11th term and the 21st term of an A.P. are 16 and 29 respectively.
__________________________
- the 41th term of that A.P.
__________________________
Let a be the First Term
& Let d be the Common Differences
↪11th Term of A.P = a + 10d = 16 ___(EQ.1)
↪21th Term of A.P = a + 20d = 29 ___(EQ.2)
BY COMPARING THE EQUATIONS,
↪10D= 13
↪D = 13/10
__________________________
Putting the value of D in (EQ.1)
↪a=3
Then,
41th Term would be a + 40D
↪41th Term = 3 + 40 ( 13/10)
↪41th Term = 44(13/10)
↪41th Term = 55