3 + 2 + 1 + 2 = 8, which is the amount of sweaters.
The probability of a brown sweater is 2 / 8 = 0.25
And the probability of a green sweater is 1 / 8 = 0.125.
Multiply the two probabilities together to get the probability of choosing brown then green:
0.25 * 0.125 = 0.03125.
To convert a decimal to fraction, you multiply the numerator and denominator, or in this case
Which can be simplified to:
Hope this helps.