Topic: Sequences and Series (Test 1)



Topic: Sequences and Series
Q.1
The next term of the sequence 1, 2, 4, 7,11,…. Is
A. 15
B. 16
C. 14
D. 18
Answer : Option B
Explaination / Solution:

here, 

where n = 1,2,3,....

so, for 6th term n = 6

 


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Q.2
If a, 4, b are in A.P.; a, 2, b are in G.P.; then a, 1, b are in
A. A.P.
B. G.P.
C. None of these
D. H.P.
Answer : Option D
Explaination / Solution:

As a,4,b are in AP so, ................(i)

Also a,2,b are in GP so, ab = 4...................(ii)

from (i) and (ii)


hence a, 1 , b are in HP


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Q.3

For what value of b, will the roots of the equation cos x = b,  when arranged in ascending order of their magnitudes, form an A.P?


A. 12
B. 12
C. 32
D. -1
Answer : Option D
Explaination / Solution:



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Q.4
If a, b , c are in A.P. and also  are in A. P., then
A. a ≠ b = c
B. a = b = c
C. a = b ≠ c
D. a ≠ b ≠ c
Answer : Option B
Explaination / Solution:



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Q.5
Sum of all 2 digit odd numbers is
A. 5049
B. 2530
C. 4905
D. 2475
Answer : Option D
Explaination / Solution:



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Q.6
The sum of first four terms of an A. P. is 56 and sum of last four terms is 112. If the first term is 11, then the number of terms is
A. 10
B. 11
C. 12
D. None of these
Answer : Option B
Explaination / Solution:



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Q.7
the ratio of first to the last of n A.m.’s between 5 and 35 is 1 : 4. The value of n is
A. 19
B. 10
C. 11
D. 9
Answer : Option D
Explaination / Solution:

the sequence is 

here a=5 and b=35

we know that, 

According to question, 



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Q.8
The next term of the sequence 1, 5, 14, 30, 55, …… is
A. 95
B. 80
C. 91
D. 90
Answer : Option C
Explaination / Solution:



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Q.9
If the numbers a,b,c,d,e are in A.P then find the value of a-4b+6c-4d+e
A. 0
B. 1
C. -1
D. 2
Answer : Option A
Explaination / Solution:



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Q.10
The nth term of the sequence 5 + 55 + 555 + …. is
A. 5×10n1
B. 59[10n1]
C. 5×11n1
D. None of these
Answer : Option B
Explaination / Solution:



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