Question

A printer prints 28 photos in 8 minutes. how many photos does it take to print 21 more photos

Answer 1

directly proportional

photos _______ minutes
28 -------------------- 8
21 -------------------- t

$\frac{28}{21} = \frac{8}{t}$

Multiply cross

$28*t = 21*8$
$28t = 168$
$t = \frac{168}{28}$
$\boxed{t=6}$


To print twenty-one photos will take six minutes