20 tonnes of a mixture of sand and gravel is
30% Sand. How many tonnes
of sand must be added
to produce
a mixture which is 40%gravel?​

Aboard game uses a fair six-sided die and a spinner with five equal-sized sections colored dark blue, green, light blue, red, and yellow. players roll the die and then spin the spinner. match each probability statement to its correct value.

Abacteria population is tripling every hour. by what factor does the population change in 1/2 hour? select all that apply

Two cars which are 40 miles apart start moving simultaneously in the same direction with constant speeds. if the speed of the car which is behind is 56 mph and the speed of the other car is 48 mph, how many hours will it take for the car which is behind to catch up the car ahead of it?