posted by peter .
One package of water plants is recommended for 3000 cubic centimeters of water in a fish tank.How many packages of plants will be needed for a 45 cm by 70 cm tank that is filled to a depth of 10 cm?
volume of given tank
= (45)(70)(10) cm^3
= 31500 cm^3
number of packages = 31500/3000
but since we probably can't buy half a package,
there will be 11 packages needed