The 7th and 21st terms of an AP are 6 and -22 respectively. Find the 26th term
A. -34
B. -32
C. -12
D. -10
E. -16
Answer: Option B
Solution(By Examveda Team)
7th term = 6 21st term = -22 That means, 14 times common difference or -28 is added to 6 to get -22 Thus, d = -2 7st term = 6 = a + 6d Or, a + (6 × -2) = 6 Or, a = 18 26st term = a + 25d = 18 -25 × 2 = -32This Question Belongs to Arithmetic Ability >> Progressions
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Related Questions on Progressions
Find the first term of an AP whose 8th and 12th terms are respectively 39 and 59.
A. 5
B. 6
C. 4
D. 3
E. 7
The sum of the first 16 terms of an AP whose first term and third term are 5 and 15 respectively is
A. 600
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Given:-
a7=6
a21=-22
Solution:-
a7=6
a+(7-1)d=6
a+6d=6..... . i
a21=-22
a+20d=-22.......ii
sub ii from i
a+6d-(a+20d)=6-(-22)
a+6d-a-20d=6+22
-14d=28
d=-2
putting value of d in equation i
a+6d=6
a+6×(-2)=6
a-12=6
a=6+12
a=18
now we have to find a26
a26=a+25d
a26=18+25×(-2)
a26=18-50
a26=-32
The 26th term is -32