Tag: properties and patterns of perfect squares

Questions Related to properties and patterns of perfect squares

Multiple choice maths fun with numbers some special sequences triangular numbers properties and patterns of perfect squares

Find the sum of:
$1+3+5+7+9+11+13+15+17+19+21+23$

  1. $11^2$
  2. $12^2$
  3. $10^2$
  4. $13^2$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
$S _{n}=\dfrac{n}{2}\left [ 2a+(n-1)d \right ]$
$a =$ First term
$d =$ Common difference
$n =$ number of terms

Given series is an A.P.
with first term $=$ $1$
common difference $=$ $2$
and last term $=$ $23$

Sum $=$ $\dfrac{12}{2}$ $\times$ $(2+11\cdot 2)$ $=$ $12\times12$
Hence, Option B is correct.

Multiple choice maths fun with numbers some special sequences triangular numbers properties and patterns of perfect squares

When we combine two consecutive triangular numbers, we get a __________.

  1. square number

  2. consecutive number

  3. non square number

  4. zero

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Triangular numbers are obtained by continued summation of natural numbers $1,2,3,4,5,6,7,.....$ 

$\therefore$ Set of triangular numbers is $1,3,6,10,15,21,28.....$
When we add two triangular numbers we get a Square number. 

For example, $1+3=4=2^2$,   $3+6=9=3^2$,   $6+10=16=4^2$ and so on.....
Hence, option A is correct.