18/ (A) Find the 20th term of the A.P. whose 3rd term is 7 and the seventh term exceeds
three times. The 3rd term by 2. Also find nth term.
(OR)
Answers
Answered by
5
Answer:
Step-by-step explanation:
a3=a+2d=7{equation 1}
3×a3=a7+2
3×7=a+6d+2
a+6d=19(equation 2)
Equation 2-1
a+6d-(a+2d)=19-7
4d=12
d=3
Put d=3 in equation 1
a+2×3=7
a=1
Therefore nth term = 1+(n-1)3
= 1+3n-3
=3n-2
Similar questions