The mean weight per student in a group of seven students is 55 kg.
If the individual weights of six students are 52, 58, 55, 53, 56 and 54, then the weight of the seventh student is
55 kg
60 kg
57 kg
50 kg
The total weight of seven students is 55×7=385 kg
The sum of the weight of six students is
52+58+55+53+56+54=328 kg
Hence, the weight of the seventh student is 385-328=57kg