If 3 students averaged 68 on a test and 4 students averaged 75, what is the average of all 7 students

A=70

B=71

C=72

D=73

E=74

Option C

Step-by-step explanation:

Total score for 3 students will be given by the product of average and frequency.

Total score for three students will then be 68*3=204

Similarly, for 4 students, their total score will also be given by

4*75=300

Adding the total score for the two groups

300+204=504

To get the average of all the 7 students, we divide the total score by frequency hence 504/7=72

Therefore, option C is correct