Question 26
1. $N\lt 40$ people participate in a math test. The sufficiency is set at 65. The results of the test are as follows: the average of all participants is 66, that of the promoted 71 and that of the rejected 56. However, due to an error in the formulation of a question, all the scores are increased of 5. At this point the average of the promoted becomes 75 and that of the non-promoted 59.
a) find all the possible values of $N$.
b) find all the possible values of $N$ in the event that, after the increase, the average of the promoted companies had become 79 and that of the non-promoted 47.
a) find all the possible values of $N$.
b) find all the possible values of $N$ in the event that, after the increase, the average of the promoted companies had become 79 and that of the non-promoted 47.