Question

Question:-

How many consecutive natural numbers starting from one should be added to get 300?

Answer 1

$\bf\purple{QuestioN\bigstar:-}$

How many consecutive natural numbers starting from one should be added to get 300?

$\bf\pink{AnsweR\bigstar:-}$

The concept we used here is,

$\Large{\boxed{\bf{\longmapsto\dfrac{n(n+1)}{2}}}}}$

Then, according to the given question,

$\bf\longmapsto{\dfrac{n(n+1)}{2}=300}$

$\longmapsto\bf{n^2+n=300\times2}$

$\longmapsto\bf{n^2+n=600}$

$\longmapsto\bf{n^2+n-600=0}$ [Equation formed here]

Now we got an equation here.

So, now we can use another concept here. That is,

$\Large{\boxed{\bf{n=\dfrac{-b∓\sqrt{b^2-4ac}}{2a}}}}}$

Here,

• a = 1

• b = 1

• c = 600

$\longmapsto\bf{n=\dfrac{-1∓\sqrt{1^2-4\times1\times-600}}{2\times1}}$

$\longmapsto\bf{n=\dfrac{-1∓\sqrt{1+2400}}{2}}$

$\longmapsto\bf{n=\dfrac{-1∓\sqrt{2401}}{2}}$

$\longmapsto$ n = -1 ∓ 49/2

$\longmapsto\bf{n=\dfrac{-1+49}{2}~/~ \dfrac{-1-49}{2}}$

$\longmapsto\bf{n=\dfrac{48}{2}~/~ \dfrac{-50}{2}}$

$\longmapsto\bf{n=24~/~ -25}$

Number of natural numbers can't be negative.

So the answer is 24.

Happy Learning!

Answer 2

Answer:

let the first no. be = x

and second no. = x+1

so, x+x+1 = 300

2×+1 = 300

2x = 300 - 1

2x = 299

x= 299/2

x= 149.5

so second no. be 149.5 + 1

= 150.5

Step-by-step explanation:

please tell me which class question this is

I from 6 class