Mathematics · Quantitative Aptitude

Number Sums and Series

287 Questions

Number sums and series questions test the ability to find patterns and calculate the sum of number sequences. These problems are a staple in the quantitative aptitude sections of various competitive exams. Practice this collection to improve speed and accuracy in solving arithmetic and geometric series problems.

Sum of consecutive integersGeometric series sumsRatio and proportion sumsOdd and even number propertiesRoman numeral calculations

Number Sums and Series Questions

Multiple choice

What is the sum of 7 and 3?

  1. 9

  2. 10

  3. 11

  4. 12
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

7 + 3 = 10.

Multiple choice

If the sum of three consecutive integers is 39, what is the largest integer among them?

  1. 14

  2. 15

  3. 16

  4. 17
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let the three consecutive integers be x, x+1, and x+2. According to the given information, x + (x+1) + (x+2) = 39. Simplifying this equation, we get 3x + 3 = 39. Subtracting 3 from both sides, we get 3x = 36. Dividing both sides by 3, we get x = 12. Therefore, the largest integer among them is x+2 = 12+2 = 14.

Multiple choice

What is the formula for the sum of the first n natural numbers, as given by Bhaskara II?

  1. $\text{Sum} = \frac{n(n+1)}{2}$
  2. $\text{Sum} = \frac{n(n-1)}{2}$
  3. $\text{Sum} = \frac{n(n+2)}{2}$
  4. $\text{Sum} = \frac{n(n-2)}{2}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Bhaskara II's formula for the sum of the first n natural numbers is $\text{Sum} = \frac{n(n+1)}{2}$. This formula is still used today in mathematics.

Multiple choice

Find the sum of the first 100 positive integers.

  1. 5050

  2. 5150

  3. 5250

  4. 5350
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The sum of the first 100 positive integers can be found using the formula: (Sum = \frac{n(n+1)}{2}), where (n) is the number of integers. Plugging in (n = 100), we get: (Sum = \frac{100(100+1)}{2} = \frac{100(101)}{2} = 5050).

Multiple choice

What is the name of the sequence in which each number is the sum of the two preceding ones, starting with 0 and 1?

  1. Fibonacci Sequence

  2. Pythagorean Sequence

  3. Euler Sequence

  4. Descartes Sequence
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The Fibonacci Sequence is a sequence in which each number is the sum of the two preceding ones, starting with 0 and 1.

Multiple choice

What is the sum of the first 100 positive integers?

  1. 5050

  2. 5150

  3. 5250

  4. 5350
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The sum of the first n positive integers is given by the formula n(n+1)/2. Therefore, the sum of the first 100 positive integers is 100(101)/2 = 5050.

Multiple choice

What is the sum of the first 100 positive integers?

  1. 5050

  2. 5150

  3. 5250

  4. 5350
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The sum of the first n positive integers is given by the formula n(n+1)/2. For n = 100, the sum is 100(101)/2 = 5050.

Multiple choice

Find the sum of all the factors of 12.

  1. 28

  2. 36

  3. 42

  4. 48
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The factors of 12 are 1, 2, 3, 4, 6, and 12. The sum of these factors is 1 + 2 + 3 + 4 + 6 + 12 = 28.

Multiple choice

Find the sum of the first $100$ positive integers.

  1. $5050$
  2. $5150$
  3. $5250$
  4. $5350$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The sum of the first $n$ positive integers is given by the formula $S_n = \frac{n(n+1)}{2}$. Substituting $n = 100$, we get $S_{100} = \frac{100(101)}{2} = 5050$. Therefore, the sum of the first $100$ positive integers is $5050$.

Multiple choice

What is the sum of the entries in the first 10 rows of Pascal's Triangle?

  1. 1023

  2. 1024

  3. 2047

  4. 2048
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The sum of the entries in the first 10 rows of Pascal's Triangle is equal to 2^10 - 1 = 2047.

Multiple choice

What is the sum of the first 100 positive integers?

  1. 5050

  2. 5150

  3. 5250

  4. 5350
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The sum of the first 100 positive integers is equal to (100 * 101) / 2 = 5050.

Multiple choice

What is the sum of the first 100 even positive integers?

  1. 2525

  2. 2575

  3. 2625

  4. 2675
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The sum of the first 100 even positive integers is equal to (100 * 101) / 2 = 2525.

Multiple choice

What is the sum of the first 100 odd positive integers?

  1. 2525

  2. 2575

  3. 2625

  4. 2675
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The sum of the first 100 odd positive integers is equal to (100 * 101) / 2 + 100 = 2575.

Multiple choice

What is the symbol for the sum of a series of numbers?

  1. ∑

  2. ∫

  3. ∏

  4. √
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The symbol ∑ is used to represent the sum of a series of numbers.

Multiple choice

What is the sum of the first 100 positive integers?

  1. 5050

  2. 5150

  3. 5250

  4. 5350
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The sum of the first n positive integers is given by the formula n(n+1)/2. Therefore, the sum of the first 100 positive integers is 100(101)/2 = 5050.