What's the rate and unit rate for 40 meters in 16 seconds

Abike shop sells you a bicycle for $63 and a helmet for $21. the total cost is 150% of what the shop spent originally. how much did the shop spend originally? how much profit did the bike shop earn by selling the bicycle and helmet to you ?

Tim open up a new saving account with a $50 deposit and plant to deposit $20 per week into the same account. write an expression to represent the total amount in his savings account.

Tom can paint the fence in 12 hours, but if he works together with a friend they can finish the job in 8 hours. how long would it take for his friend to paint this fence alone?