If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

## Algebra (all content)

### Course: Algebra (all content)>Unit 7

Lesson 18: Modeling situations by combining and composing functions (Algebra 2 level)

# Model with composite functions

## Problem

Mason is a captain of a tourist cruise to the Statue of Liberty. He saw and modeled the following relationships.
FunctionInputOutput
PDuration of the cruise, rAverage number of photos taken by each passenger, P, left parenthesis, r, right parenthesis
DSpeed of the ship, kDuration of the cruise, D, left parenthesis, k, right parenthesis
SRate of the river current, xSpeed of the ship, S, left parenthesis, x, right parenthesis
The expression D, left parenthesis, S, left parenthesis, x, right parenthesis, right parenthesis represents which of the following?