When Natasha saves $13 more, she will have enough money to buy a basic MP3 player. The player she wants to buy costs $204, which is three times the cost of the basic player. Which equation could be used to determine n, the number of dollars Natasha has already saved? A: n + 13 = 3(204)
B: 3(n + 13) = 204
C: n + 3(13) = 204
D: 3n + 13 = 204

What is the lcm of 16 and 40 ? 24 and 40 ?

Precalculus question, image attached.

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.