Question

A solid is in the form of a cone of vertical height $9cm$ mounted on the top base of a right circular cylinder of height $40cm$. The radius of the base of the cone and that of the cylinder are both equal to $7cm$. Find the weight of the solid if $1c{m}^3$ of the solid weighs $4gm.$

• A. $26.488kg$
• B. $25.488kg$
• C. $24.488kg$
• D. $23.488kg$

Answer 1

The correct option is A $26.488kg$

Volume of cylinder$=\pi {r_1}^2{h}_1=\frac{22}{7}\times 7\times 7\times 40=6160{cm}^2$
volume of cone$=\frac{1}{3}\pi r^{2}h=\frac{1}{3}\times \frac{22}{7}\times 7^2\times 9=22\times 7\times 3=462{cm}^3$
Total volume$=6160+462=6622{cm}^3$
Total weight$=$volume$\times$ weight per ${cm}^3.=6622\times 4=26488gm=26.488kg$