Answer:
p = x * (3/8)
Where p is the amount of a box and x is the number of people.
For x=2 -> p = 2 * (3/8) = 3/4
Explanation:
If Mark uses 3/8 of a box to make enough for one person, we can find the amount required (p) to be enough for 'x' people using a rule of three:
3/8 of a box -> 1 person
p -> 'x' people
(3/8)/p = 1/x
p/(3/8) = x
p = x * (3/8)
If we want the amount for 2 people, we use x = 2 in the equation:
p = 2 * (3/8) = 3/4
So Mark will need 3/4 of a box.