Question

Q11)What is the sum of the
first 25 natural numbers ? *​

Answer 1

ANSWER:

• The sum of the first 25 natural numbers = 325.

TO FIND:

• The sum of the first 25 natural numbers.

EXPLANATION:

METHOD 1:

${\boxed{\bold{Sum \ of \ n \ natural \ numbers = \dfrac{n(n+1)}{2}}}}$

n = 25 [ we want to find the sum of 25 natural numbers ]

Sum = 25(25 + 1) / 2

Sum = 25(26) / 2

Sum = 25(13)

Sum of 25 natural numbers = 325

METHOD 2:

We can solve this also by using A.P formula

Sₙ = n/2(2a + (n - 1)d)

a = 1 [ Natural numbers start with one ]

d = 1 [ Difference between consequtive terms in one ]

n = 25

S₂₅ = 25/2 ( 2(1) + (25 - 1)1)

S₂₅ = 25/2 ( 2 + (24)1)

S₂₅ = 25/2 (26)

S₂₅ = 25(13)

S₂₅ = 325

HENCE SUM OF FIRST 25 NATUTAL NUMBERS IS EQUAL TO 325.