2 litres every 2.5 minutes is 4 litres every 5 minutes so therefore, it is 0.8 litres/minute (800ml per minutes)
area of a circle is PI x r^2
2 = d/2 = 5.4/2 = 2.7 cm
using 3.14 for PI
3.14 x 2.7^2 = 22.89 square inches
360 degree in a circle, shaded area is 180 degree, which is 50%
so 22.89 x .5 = 11.45 cm^2
Let the number of half dollars be x,
number of quarters = x + 2
amount of half dollars = 0.5x
amount of quarters = 0.25(x + 2)
= 0.25x + 0.5
total amount = 0.5x + 0.25x + 0.5
= 0.75x + 0.5
0.75x + 0.5 = 11.75
0.75x = 11.25
x = 15
number of quarters = x + 2
= 15 + 2
= 17
There are 17 quarters and 15 half dollars.