Banner 0
Banner 1
Banner 2
Banner 3
Banner 4
Banner 5
Banner 6

Q.

State True/False.


If 4 times the 4th term of an AP is equal to 18 times its 18 th term then its 22nd term is 0.


see full answer

Talk to JEE/NEET 2025 Toppers - Learn What Actually Works!

Real Strategies. Real People. Real Success Stories - Just 1 call away
An Intiative by Sri Chaitanya

a

False  

b

True

answer is A.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

Given that, 4 times the 4th term of an AP is equal to 18 times its 18 th term.
According to the given condition:
4× t 4 =18× t 18 (1)
Let a be the first term and d be the common difference of the A.P.
Formula for the n th term:
t n =a+ n1 ×d
Applying the formula of n th term of AP and calculate the 4th term. t 4 =a+(41)d t 4 =a+3d(2)
Applying the formula of n th term of AP and calculate the 18th term.      t 18 =a+(181)d t 18 =a+17d(3) Applying the formula of n th term of AP and calculate the 22th term. t 22 =a+(221)d(4)
Put the value of t 4 from equation (2) and the value of t 18 from equation (3) into equation (1):
4(a+3d)=18(a+17d) 4a+12d=18a+306d 14a=294d a=21d
  a+21d=0 a+(221)d=0(5)
Put a+(221)d= t 22  from equation (4) in equation (5) ,  Thus, t 22 =0 .
Therefore, 22nd term of A.P. is 0.
Thus, the given statement is true.
Hence, option (1) is correct.
 
Watch 3-min video & get full concept clarity

Best Courses for You

JEE

JEE

NEET

NEET

Foundation JEE

Foundation JEE

Foundation NEET

Foundation NEET

CBSE

CBSE

score_test_img

Get Expert Academic Guidance – Connect with a Counselor Today!

whats app icon