Sequences, Series & Reasoning
16 questions available
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Q1.2x1(2)+4x2(2)+6x3(2)..................20x10(2)?
Correct Answer: A
Q2.Complete the series ,7,13,21,--------43,57:
Correct Answer: A
The pattern is +6, +8, +10, +12, +14: 7+6=13, 13+8=21, 21+10=31, 31+12=43, 43+14=57.
Q3.What is the incorrect value of the given series:2,4,7,14,17,34,37,64
Correct Answer: B
Pattern: ×2, +3, ×2, +3... 2×2=4, 4+3=7, 7×2=14, 14+3=17, 17×2=34, 34+3=37, 37×2=74 (not 64).
Q4.The first term in a sequence is 1 and the second term is 5. From the third term onwards, each term is the average (arithmetic mean) of all preceding terms. What is the 27th term in the sequence?
Correct Answer: B
After the first two terms, every subsequent term equals the running average, so the sequence quickly settles near a stable average value of 3 by the 27th term.
Q5.What is the next term in the series: 11, 20, 38, 56, 83?
Correct Answer: D
The differences between terms increase by 9 each time (9,18,18,27...); following the pattern, the next term is not among (a),(b),(c), so 'None of these' is correct.
Q6.What is a and b in the given sequence? a, 13, 9, 3, -5, -15, b
Correct Answer: B
Correct answer is B: 15, -27
Q7.Find the answer of the series (-3) x (-3) x (-3):
Correct Answer: C
Correct Answer: -27.
Q8.Who introduced the term "Intelligence Quotient" (I.Q)?
Correct Answer: A
Correct Answer: William Stern.
Q9.Short-term memory lasts only:
Correct Answer: C
Correct Answer: 20-30 seconds.
Q10.Give the name of the term "SPM" which is often used in the study of pollution:
Correct Answer: C
Correct Answer: Suspended Particulate Matter.
Q11.Complete the series: 1/3, 2/7, 4/15, 8/31, ___, 32/127:
Correct Answer: A
Q12.Find the 8th term of the series 1, 3, 9, ...
Correct Answer: A
This is a GP with a=1 and r=3. The nth term formula is an = a * r^(n-1). For n=8: a8 = 1 * 3^7 = 2187.
Q13.An arithmetic progression has 2nd term = 20 and 8th term = 60. What is the 20th term?
Correct Answer: B
AP formula: T_n = a + (n-1)d. T_2 = a + d = 20. T_8 = a + 7d = 60. Difference: 6d = 40 => d = 20/3, and a = 40/3. T_20 = a + 19d = 40/3 + 380/3 = 420/3 = 140.
Q14.If the 3rd term of AP is 8 and 6th term of AP is 17, what is the 8th term of AP?
Correct Answer: B
T_3 = a + 2d = 8, T_6 = a + 5d = 17. Difference: 3d = 9 => d = 3. Finding first term: a + 6 = 8 => a = 2. 8th term: T_8 = a + 7d = 2 + 7(3) = 23.
Q15.The virus spreads rapidly in the town. It infected the people - First day: 8, Second day: 16, Third day: 32. What will be the number of people infected on the next day?
Correct Answer: C
The sequence doubles each day: 8 * 2 = 16, 16 * 2 = 32. The next day is 32 * 2 = 64 people.
Q16.What is the formula for the nth term of a Geometric Progression (G.P)?
Correct Answer: B
The nth term of a Geometric Progression is given by a × r^(n-1), where 'a' is the first term and 'r' is the common ratio.