X = 57. Use the rules for inscribed angles. If that exterior angle is 123, then its supplement is 57. That 57 degree inscribed angle has an intercepted arc that is also the same arc that angle x intercepts. So x has the same measure as the other inscribed angle. Your answer is B.
The awnser is 1000 because 60 miutes in an hour, 50 mouse traps every half hour so 100 mouse traps an hour multiply that by 10 and you get 1000, i think.
