directly proportional
photos _______ minutes
28 -------------------- 8
21 -------------------- t
[tex] \frac{28}{21} = \frac{8}{t} [/tex]
Multiply cross
[tex]28*t = 21*8[/tex]
[tex]28t = 168[/tex]
[tex]t = \frac{168}{28} [/tex]
[tex]\boxed{t=6}[/tex]
To print twenty-one photos will take six minutes
