Number Series MCQs with Answers

What is the value of $k$ in the sequence $1, 5, 11, 19, k, 41, 55$?

• A.$27$
• B.$33$
• C.$31$
• D.$29$

Find the missing number in the series: $5, 7, 8, 10, 11, \_, 13$

• A.$14$
• B.$9$
• C.$12$
• D.$15$

Complete the number series: $1, 6, 13, 22, 33, \_\_\_\_\_\_?$

• A.$44$
• B.$45$
• C.$46$
• D.$48$

Which of the following is an arithmetic sequence?

• A.$2, 4, 8, 16$
• B.$1, 1, 2, 3, 5$
• C.$31, 32, 33, 34$
• D.$1, \frac{1}{2}, \frac{1}{4}, \frac{1}{8}$

If $12 \times 21 = 9$, $23 \times 32 = 25$, then $34 \times 43 =$ _?

• A.$36$
• B.$49$
• C.$64$
• D.$81$

Find the sum of the first 10 terms of the geometric sequence $3, 6, 12, 24, \dots$

• A.$3069$
• B.$3072$
• C.$3056$
• D.$3081$

In an arithmetic progression (A.P.), if $a = 3$, $d = 6$, and $n = 9$, find $T_n$.

• A.$45$
• B.$51$
• C.$57$
• D.$63$

The sum of squares of all numbers from 1 to 50 is:

• A.An even number
• B.An odd number
• C.A prime number
• D.A perfect square

Maclaurin's series expansion of $\cos x$ is ?

• A.$\cos x = 1 + \frac{x^2}{2!} + \frac{x^4}{4!} + \frac{x^6}{6!} + \cdots$
• B.$\cos x = x - \frac{x^3}{3!} + \frac{x^5}{5!} - \frac{x^7}{7!} + \cdots$
• C.$\cos x = 1 - \frac{x^2}{2!} + \frac{x^4}{4!} - \frac{x^6}{6!} + \cdots$
• D.$\cos x = 1 - \frac{x}{1!} + \frac{x^2}{2!} - \frac{x^3}{3!} + \cdots$

The ratio test and root test fail when the limit of the ratio of $(n+1)$th and $n$th terms of the series becomes _?

• A.$0$
• B.$\infty$
• C.$1$
• D.$-1$