A student observed the apparent shape of the moon every night for a period of 60 days. On Day 10 the student observed a full moon. On which day did the student most likely observe a full moon?

A. Day 20
B. Day 30
C. Day 40
D. Day 50

I think it's C cause it takes about 30 days to see a full moon again

2 answers

Right!
It is actually 27.3 days + Day 10.

I don't like your choices, but the best is as you indicated.