Physical science : find the speed of an object that covers 400 km in 5 hr.
a. 40 km/hr
b. 80 km/hr
c. 2000 km/hr
d. 800 km/hr

Can someone me my sister? she is in third grade. 50 points and brainlist! ones that are not answered. plz and thx!

Element x decays radioactively with a half life of 8 minutes. if there are 450 grams of element x, how long, to the nearest tenth of a minute, would it take the element to decay to 37 grams?

Aformual for 8 bottles of window cleaner calls for 6 cups of rubbing to customers alcohol 2 1/4 gallons of water and 1 1/2 cups of ammonia alcohol would the forula call if a factory made 1,280 bottles for stores to sell to customers