Find the missing term in the following series.
361, 289, 169, ____, 49
Series Missing Term Identification
The question asks to identify the missing term in the numerical series: 361, 289, 169, ____, 49.
Analyzing the Series Pattern
- Observe the given numbers: 361, 289, 169, 49.
- Recognize that these numbers are perfect squares.
- Calculate the square roots of the known terms:
- $\sqrt{361} = 19$
- $\sqrt{289} = 17$
- $\sqrt{169} = 13$
- $\sqrt{49} = 7$
- Examine the sequence of the square roots: 19, 17, 13, ?, 7.
- Notice that these roots are prime numbers in descending order.
- The sequence of prime numbers is 19, 17, 13, 11, 7.
- The missing prime number in the sequence is 11.
Calculating the Missing Term
The missing term in the original series corresponds to the square of the missing prime root (11).
- Calculate the square of 11: $11^2 = 121$.
Therefore, the missing term in the series is 121.
Important Questions from Number Series
Select the number from among the given options that can replace the question mark (?) in the following series.
15, 45, 75, 105, ?
Identify the number that does NOT belong to the following series.
18, 27, 35, 45, 54
Select the number from among the given options that can replace the question mark (?) in the following series.
37, 41, 50, 66, ?
दिए गए विकल्पों में से वह संख्या चुनिए जो निम्नलिखित श्रृंखला में प्रश्नवाचक चिन्ह (?) को प्रतिस्थापित कर सके।
20, 21, 25, 34,?, 75
Select the correct option that will fill in the blank and complete the series.
45, 49, 58, 74, .........
