Sequences and Series - Online Test
Q1. The next term of the sequence 1, 2, 4, 7,11,…. Is
Answer : Option B
Explaination / Solution:
here,
where n = 1,2,3,....
so, for 6th term n = 6
Q2. The next term of the sequence, 2, 6, 12, 20, …..is
Answer : Option D
Explaination / Solution:
nth term of given sequence is n(n+1)
so the 5th term is 5(5+1)=30
Q3. The next term of the series is
Answer : Option B
Explaination / Solution:
Terms of given sequence can be written as
so the required term is 33/32
Q4. Which term of the sequence 8 – 6i, 7 – 4i, 6 – 2i, ….is a real number ?
Answer : Option D
Explaination / Solution:
for real n, imaginary part = 0
so 2n - 8=0
which gives, n = 4
Q5. All the terms in A.P., whose first term is a and common difference d are squared. A different series is thus formed. This series is a
Answer : Option B
Explaination / Solution:
the series obtained will not follow rules of AP, GP and HP
Q6. If a, 4, b are in A.P.; a, 2, b are in G.P.; then a, 1, b are in
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
Q7. The eleventh term of the sequence 1, 1, 2, 3, 5, 8, 13, 21, 34, ….. is
Answer : Option C
Explaination / Solution:
here,
Q8. pth term of an A.P. is q and qth term is p, its (p+ q)th term is
Answer : Option B
Explaination / Solution:
Q9. The sum of 40 A.M.’s between two number is 120. The sum of 50 A.M.’s between them is equal to
Answer : Option B
Explaination / Solution:
sum of n number of A.M's between two numbers a and b is given by
so,
therefore sum of 50 A.M's between a and b is,
Q10. In an A.P., sum of first p terms is q and sum of first q terms is p. Sum of its p + q terms is
Answer : Option D
Explaination / Solution:
