Subject: mathqa
Question: the average height of 30 students in a class was calculated as 177 cm . it has later found that the height of one of the students in the class was incorrectly written as 151 cm whereas the actual height was 106 cm . what was the actual average height of the students in the class ?
Option: 
A: 172.5 cm
B: 175.5 cm
C: 174.5 cm
D: 176.5 cm
Answer: B