Number of different 5 digit combinations if successive digits msut be different

When 142 is added to a number the result is 64 more times the number my options are 35 37 39 41

Secant ac and bd intersect at point e inside f what is the measure of aed if measurements cd equals 30 a b is 50 and cb is 170

An automobile assembly line operation has a scheduled mean completion time, μ, of 12 minutes. the standard deviation of completion times is 1.6 minutes. it is claimed that, under new management, the mean completion time has decreased. to test this claim, a random sample of 33 completion times under new management was taken. the sample had a mean of 11.2 minutes. assume that the population is normally distributed. can we support, at the 0.05 level of significance, the claim that the mean completion time has decreased under new management? assume that the standard deviation of completion times has not changed.