Tricia reads $20$20 pages of her book in $2$2 hours.
Which of the following is the unit rate of pages per hour?
$10$10 pages/hr
$2$2 pages/hr
$20:2$20:2
$10:1$10:1
A car travels $320$320 km in $4$4 hours.
A tap fills up a $240$240 litre tub in $4$4 hours.
A toy manufacturer makes $720$720 toys in $9$9 hours.