Final Answer:
Kevin will use 1/3 of the orange juice per day. So, using the same amount for 3 days, he will use 1/3*3 = 1 unit of orange juice in total.
Step-by-step explanation:
When Kevin has exactly enough orange juice for 1 day, using the same amount for 3 days means each day he uses 1/3 of the total amount. Thus, in total, he uses 1/3*3 = 1 unit of orange juice.
Kevin having enough orange juice for 1 day implies the entire juice volume sustains him for a single day's consumption. Therefore, using the same amount for 3 days implies dividing the total juice evenly across these days, resulting in 1/3 of the juice being consumed each day.
Multiplying the fraction representing the juice used per day 1/3 by the number of days (3) reveals the total amount consumed. 1/3* 3 = 1 unit of orange juice used in total.
The concept of proportionality comes into play here, indicating that if the same quantity suffices for a single day, it will be used thrice when extended over three days. Hence, 1/3 of the juice per day utilized over 3 days amounts to the entirety of the initial juice quantity.
In summary, by utilizing 1/3 of the juice each day for 3 days, Kevin exhausts the entirety of his initially available orange juice, using a total of 1 unit in that time frame.