#17 i need if you answer this you will get 16 points

7. (a) which hr did more leave then arrive3:00 - 4:0030 left and 18 arrived

(b) 75 customers in the store at 1:0030 entered, 12 left75 + 30 - 12 = 93, so at 2:00, there is 93 customers...14 entered, 8 left93 + 14 - 8 = 99...so at 3:00, there are 99 customers...18 entered, 30 left99 + 18 - 30 = 87so at 4:00, there were 87 customers in the storeso, between 4:00 and 5:00, there are 87 customers that need to leave 

Is there a picture because i cannot answer it sorry