The strength of a beam varies inversely with the square of i

The strength of a beam varies inversely with the square of its length. If a 10-foot beam can support 600 pounds, how many pounds can an 11-foot beam support? Round the answer to the nearest pound. An 11-foot beam can support pounds.

Solution

Strength = k(1/length^2)
If length = 10, then strength = 600
600 = k/10^2
k = 6 *(10^4)

So : Strength = 6*10^4/length
If length = 11 ,
Strength = 6*10^4/11^2 =495.87