NIMCET 2011 — Reasoning PYQ
NIMCET | Reasoning | 2011In the following number-series, one term is wrong. Which term is wrong ?
5, 12, 19, 33, 47, 75, 104
Choose the correct answer:
- A.
33
- B.
47
- C.
75
- D.
104
(Correct Answer)
104
Explanation
1. Analyze the pattern of the series:
The pattern follows a logic where a term is the sum of the two preceding terms (similar to a Fibonacci-type sequence).
2. Test the pattern:
-
First term: 5
-
Second term: 12
-
Third term: 5+12=17 (But the series shows 19)
-
Fourth term: 12+19=31 (But the series shows 33)
Since the later terms are also affected, let's re-verify the logic starting from the first two terms:
-
5+12=17 (If 19 is wrong and replaced by 17)
-
12+17=29 (If 33 is wrong and replaced by 29)
Let's check if there is an alternative pattern based on differences:
-
12−5=7
-
19−12=7
-
33−19=14
-
47−33=14
-
75−47=28
-
104−75=29
3. Identify the inconsistency:
Looking at the differences: 7,7,14,14,28,…
The differences are doubling every two steps:
-
Pair 1: +7,+7
-
Pair 2: +14,+14
-
Pair 3: Should be +28,+28
4. Recalculate with the identified pattern:
-
5+7=12
-
12+7=19
-
19+14=33
-
33+14=47
-
47+28=75
-
75+28=103
In the given series, the last term is 104, but according to the pattern (+7,+7,+14,+14,+28,+28), it should be 103.
Correct Option: (d) 104
