Home › UP Board Class 10 › Mathematics › A right circular cylinder circumscribes the toy …
A right circular cylinder circumscribes the toy made of a cone on a hemisphere, shown in the figure. The toy has radius $2\,\mathrm{cm}$ and cone height $2\,\mathrm{cm}$. What is the difference between the volume of the circumscribing cylinder and the volume of the toy? Use $\pi=3.14$. 
A$12.56\,\mathrm{cm}^3$
B$18.84\,\mathrm{cm}^3$
C$25.12\,\mathrm{cm}^3$
D$50.24\,\mathrm{cm}^3$
Answer & Solution
Correct answer: C. $25.12\,\mathrm{cm}^3$
The circumscribing cylinder has the same radius $2\,\mathrm{cm}$ and total height equal to cone height $+$ hemisphere radius $=2+2=4\,\mathrm{cm}$. So its volume is $\pi r^2h=3.14\times2^2\times4=50.24\,\mathrm{cm}^3$. The toy volume is $25.12\,\mathrm{cm}^3$, so the difference is $50.24-25.12=25.12\,\mathrm{cm}^3$.
Related questions
When variables and numbers appear on both sides, you must simplify:Equations needing more than one operation are described as taking more:Once a solution is found, it should be checked by substituting it back to get a statement The product of any number and its reciprocal equals:A fraction multiplying the variable is best removed by multiplying by its:Solving x divided by 4 equals 3 gives x equal to:Solving 4x equals 20 gives x equal to:Solving x minus 8 equals 5 gives x equal to: