Topics

General Knowledge
General Science
General English
Aptitude
General Computer Science
General Intellingence and Reasoning
Current Affairs
Exams
Elementary Mathematics
English Literature

Find the sum of 1+3+5+....+45

A) 540
B) 539
C) 529
D) 579

Correct Answer:



C) 529

Description for Correct answer:
1+3+5+....+45

Here a=1, d=2, l=45

\( \Large n=\frac{l-a}{d}+1 = \frac{45-1}{2}+1 = 22+1 = 23\)

Therefore, 1+3+5+....+45 = \( \Large n^{2} \)

=\( \Large 23^{2} = 529 \)

Part of solved Factorisation questions and answers : >> Elementary Mathematics >> Factorisation

Comments

Similar Questions

1). Find the sum of \( \Large 21^{2}+22^{2}+....+60^{2} \)

A). 70940

B). 2870

C). 12810

D). 9946

2). Find the sum of \( \Large 1^{3}+2^{3}+....+10^{3} \)

A). 163675

B). 3025

C). 163765

D). cannot be determined

3). Find the sum of \( \Large 15^{3}+16^{3}+....+50^{3} \)

A). 1614600

B). 1614660

C). 1614670

D). 1615676

4). Find the square root of \( \Large x^{4}+2x^{2}y^{2}+y^{4} \)

A). \( \Large x^{2}+y^{2} \)

B). \( \Large \left(x+y\right)^{2} \)

C). \( \Large x^{2}-y^{2} \)

D). None of these

5). Find the square root of \( \Large \left(a^{2}-1\right) \left(a^{2}-2a-3\right) \left(a^{2}-4a+3\right) \)

A). \( \Large \left(a+1\right) \left(a-1\right) \left(a-3\right) \)

B). \( \Large \left(a-1\right) \left(a+3\right) \left(a+1\right) \)

C). \( \Large \left(a-1\right) \left(a+1\right) \)

D). None of these

6). Which of the following is correct. The squares root of \( \Large 25x^{4}+30x^{3}+19x^{2}+6x+1 \)

A). \( \Large 5x^{2}-3x-1 \)

B). \( \Large 5x^{2}+3x+1 \)

C). \( \Large 5x^{2}+6x+1 \)

D). \( \Large 5x^{2}-6x+1 \)

7). If \( \Large 25x^{4}+20x^{3}-26x^{2}+ax+b \) is a perfect square, find the value of a and b

A). a = 12, c = 9

B). a = 12, b = 9

C). a = -12, b = 9

D). a = 6, b = 9

8). Solve: \( \Large x^{2}-121-0 \), find the value of x.

A). 11, -11

B). 6, 15

C). 11, 11

D). 12, 11

9). In a rectangle, the length of the rectangle is 10 mts more than the breadth. If the area of the rectangle is \( \Large 144 m^{2} \), then its perimeter is

A). 52 mts.

B). 54 mts.

C). 18 mts.

D). 36 mts.

10). Using the formula find the roots of the equation \( \Large 3x^{2}-4x+1=0 \)

A). \( \Large -1, \frac{1}{3} \)

B). \( \Large 1, \frac{1}{3} \)

C). \( \Large 2, \frac{2}{3} \)

D). 3, 1