A box weighed on a triple beam balance to be 400g. It has a volume of 20 ml. What is the density?

 The density is 20 g/ml

Explanation:

Density is defined as the mass contained by a substance per unit volume.

To calculate the density, we use the equation:

Mass of box = 400 g

Volume of box =  20 mL

Putting values in above equation, we get:

Thus the density is 20 g/ml

as resources become scarce because of population growth, the growth decreases after few years due to lack of resources and food.

9.9 years

a = p(1 + rt) . . account balance after time t at rate r starting with principal p

3000 = 2500(1 + 0.0202t) . . filling in the given numbers

1.2 = 1 + 0.0202t . . divide by 2500

0.2 = 0.0202t . . . subtract 1

0.2/0.0202 = t ≈ 9.901

it will take about 9.9 years for the account balance to reach $3000.