Anova with squared sum of the observations

Hey guys...during one of homeworks, I was required to perform anova while having the means of each group and only the SS (sum of squared), this:
how do I create the ssw and ssb with that data?

the data is: Mean group A: 6 (n=9) , Mean group B: 13 (n=9), Mean group C: 11 (n=9)
Last edited: