Question

the formula to find sum S of first nnatural numbers is S=n(n+1)/2. find n if sum of first n natural numbers is 300

Answer 1

n(n+1)/2=300
=>n(n+1)=300*2
=>n(n+1) = 600
=>n+1 = 600/n
=>n= 600/n -1
something like this it will come hope it helps