maths problem

Question

A basket ball team has 5 players and one reserve. the mean weight of the 5 players is 58kg the reserve weighs 64 kg whats the mean weight of all 6 players

Answer 1

(5*58+64)/6

(290+64)/6

354/6=59 kg is the mean weight of the 6 players

the mean weight of the 5 players is 58 kg

this is the same as having 5 players each one with a weight of 58 kg

(58+58+58+58+58+64)/6=354/6=59 kg again

Answer 2

in order to solve this one i would take

(5 * 58 + 64) / (5 + 1)

that way the new average is accounting for the first 5 players as well as the new player

computing that value algebraically here yields

(290 + 64) / 6

=354 / 6

=59

so the mean weight of all 6 players here is 59 kg