Question

if the sum of certain natural numbers is 210.how many natural numbers make the sum​

Answer 1

sum of n natural no=210

n(n+1)/2=210

n²+n=420

n²+n-420=0

n²+21n-20n-420=0

(n+21)(n-20)=0

n=20, ans

Answer 2

Answer:

20

Step-by-step explanation:

we know that the sum of the consecutive number is given by:

=>n(n+1)/2

so,

=>n(n+1)/2=210

=>n(n+1)=420

=>n^2+n-420=

=>n^2+21n-20n-420=0

=>n(n+21)-20(n+21)=0

=>(n-20)(n+21)=0

thus,

n=20 as n cannot be -ve.

thus,20 consecutive natural numbers make the sum 210.