This is a problem of Standard Normal distribution.
We have mean= 12 grams
Standard Deviation = 2.5 grams
First we convert 8.5 to z score. 8.5 converted to z score for given mean and standard deviation will be:

So, from standard normal table we need to find the probability of z score to be less than -1.4. The probability comes out to be 0.0808
Thus, the probability that the strawberry weighs less than 8.5 grams is 0.0808