In a class of 120 students,60 play tennis,50 play polo and 20 play both. How many play only polo?
20 play both, so only 50-20 play polo only
To find out how many students play only polo, we can subtract the number of students who play both tennis and polo from the total number of students who play polo.
Number of students who play polo = 50
Number of students who play both tennis and polo = 20
So, the number of students who play only polo = 50 - 20 = 30
Therefore, 30 students play only polo.
To find out how many students play only polo, we need to subtract the number of students who play both tennis and polo from the total number of students who play polo.
First, we know that 60 students play tennis, 50 students play polo, and 20 students play both. Let's use a Venn diagram to visualize this information.
In the diagram, we will represent the set of students who play tennis as 'T', the set of students who play polo as 'P', and the set of students who play both tennis and polo as 'TB'.
| T |
---------------
| TB |
---------------
| P |
From the given information, we know that 60 students play tennis, which includes the 20 students who play both tennis and polo (TB). So, the number of students who play only tennis (T) is 60 - 20 = 40.
Similarly, we know that 50 students play polo, including the 20 students who play both tennis and polo (TB). Therefore, the number of students who play only polo (P) is 50 - 20 = 30.
Hence, the answer is that 30 students play only polo.