i need to find the size of 2 samples based on this information

The population variance of the distribution for X is 100. 2 random samples of size n1 and n2 are repeatedly taken from the population. the sample means for sample size n1 and sample size n2 have the follwing distributions:

X ~ N(1,10)

X ~ N(1,2.5)

(X should be X with a bar over it)

any help please??