A) The radius of the hemisphere is:
r = d÷2 = 21÷2 = 10.5cm
We can now calculate the volume of a hemisphere:
V = 2/3 π r³
= 2/3 π (10.5)³
= 2423 cm³
As we can consider that 1000cm³ contains 1l, each bowl contains
2423 ÷ 1000 =2.423l.
In total, the milk served will be: 2.423 × 100 = 242l
B) The total cost will be:
242 × 10 = 2420Rs
C) Mr.and Mrs. Ramesh helped blind students using an eco-friendly material, therefore they have shown social and environmental values.