Skye is taking part in a hotdog eating competition. Which of these compound units could be used to measure how quickly she can eat hotdogs?
Select all the correct options.
hotdogs/minute
seconds/hotdog
hotdogs/glass of water
seconds/bite
A tap fills up a $240$240 litre tub in $4$4 hours.
A toy manufacturer makes $720$720 toys in $9$9 hours.
Justin earns $\$420$$420 in $6$6 hours.
Which of the following represents Justin's hourly rate?