I think this is related to the normal distribution? If so then I can proceed.
The variance in a normal distribution is equal to:
Otherwise, if you have a set of values, the formula for variance would be something completely different.
For binomial distribution...
For discrete data...
And somehow, I always forget the one with grouped data ... but there are more.
From the two values that you have, you will have to find the z score and from there, work out simultaneous equations:
0.125 is obtained from the normal table that is made available to you.
And from that and the given equation:
You can find sigma and square it to get the variance.
I will say it again, this is valid only if your problem deals with the normal distribution.