Math riddle! !

3 guys walk into a hotel. the hotel charge was $30. each guy payed $10. the owner felt bad bc they were such nice guests. so the owner gave $5 to the bell boy to give to the guys. the bell boy thought for a moment. you can't split $5 w/ 3 guys ( w/ 5 singles quickly ) so he took $2. so he gave the guys the $3. they each get $1 back. so they each paid $9 ( $27 total ) the bell boy took 2 and they paid 27 ( $29 total ) what happened to the other dollar?

Offering 30 if a plus b plus c equals 68 and ab plus bc plus ca equals 1121, where a, b, and c are all prime numbers, find the value of abc. the answer is 1978 but i need an explanation on how to get that.

The federal reserve controls certain interest rates in the united states. investors often try to speculate as to whether the federal reserve will raise or lower rates and by how much. suppose a company conducts extensive interviews with financial analysts, and as a result, predicts that "thefed" will increase rates by an average of 0.25 percentage points every six months for the forseeable future. which type of equation could be used to model the predicted interest rates over the next several years, assuming no other significant changes? a) a linear equation b) a quadratic equation c) a polynomial equation d) an exponential equation

What is the period of the sinusoidal function ?