Write an equation of the cosine function with amplitude pi/2 and period 3

What is the least common multiple of 16 and 3?

Classify the following triangle check all that apply

Abike shop sells you a bicycle for $63 and a helmet for $21. the total cost is 150% of what the shop spent originally. how much did the shop spend originally? how much profit did the bike shop earn by selling the bicycle and helmet to you ?