Question

If the mean of first n natural numbers is 3n/5then the value of n is

Answer 1

Step-by-step explanation:

The value of n = 5

Step-by-step explanation:

Given,

Mean of first n natural numbers = \bold{\frac{3n}{5}}

5

3n

We know that,

Mean of n natural numbers = \bold{\frac{n+1}{2}}

2

n+1

⇒ \bold{\frac{n+1}{2}}

2

n+1

= \bold{\frac{3n}{5}}

5

3n

⇒ 5(n + 1) = 2(3n)

⇒ 5n + 5 = 6n

⇒ n = 5

Therefore the value of n = 5

Answer 2

Answer:

mean of first natural number = (n+1)/2

Given, mean = 3n/5

now, 3n/5 = (n+1)/2

=> 6n = 5n + 5

=> n = 5