For this case we have that the complete question is:
There were 20 drinks in a cooler. Joey drank 15% of the drinks. Sandra drank 1/5 of the drinks. Hannah drank 1/4 of the drinks. Tammy drank 30% of the drinks. How many drinks are left in the cooler? a 0 b 2 c 5 d 9
We propose a rule of three:
20 ---------> 100%
x ------------> 15%
Where the variable "x" represents the amount of drinks equivalent to 15%.

So, Joey drank 3 drinks.
On the other hand, we have that Sandra drank
of the drinks:

Thus, Sandra drank 4 drinks.
In addition, Hannah drank
of the drinks:

So Hannah drank 5 drinks.
Finally, Tammy drank 30% of the drinks:
20 ---------> 100%
y ------------> 30%
Where the variable "y" represents the amount of drinks equivalent to 30%.

So Tammy drank 6 drinks.
Adding up we have:

So: 
Thus, 2 drinks remain in the refrigerator.
Answer:
Option B
I'm going to need more information before I can answer.
3.5 strip As will fit into Strip b. 2/7 strip Bs will fit into strip A
Answer: AB/y = BC/z = AC/x
Step-by-step explanation:
Side AB corresponds to side y, side BC corresponds to side z, and side AC corresponds to side x.
Answer:
In year 2039 both the events will happen again.
Step-by-step explanation:
We are given the following in the question:
Family reunion:
Every 7 year
Update the family tree:
Every 6 years
1997 was the year when they had a family reunion as well as they updated their family tree.
We have to find the year in which both the events will occur together.
We find the lowest common multiple of 7 and 6.

Thus, after 42 years both the event will happen again.
Year:

Thus, in year 2039 both the events will happen again.