Question

Find four rational numbers between -4 and -5

Answer 1

Answer:

-21/5, -22/5, -23/5, -24/5

Step-by-Step Explanation:

-4/1 = -4×5/1×5 = -20/5

-5/1 = -5×5/1×5 = -25/5

therefore,

four rational numbers b/w -4 and -5 are:-

-20/5 -21/5 -22/5 -23/5 -24/5 -25/5

answer = -21/5, -22/5, -23/5, -24/5

Answer 2

Question :-

The radius of a cylinder is 12 m and height is 21 m. Find the curved surface area of the cylinder.

Answer :-

Given :-

r = 12 cm

h = 21 cm

To Find :-

Curved surface area ( CSA )

Solution :-

Curved surface area of cylinder = 2πrh

Substituting the values in formula :-

→ \sf CSA = 2 \times \frac{22}{\cancel7} \times \cancel21CSA=2×

7

22

×

2

1

→ \sf CSA = 2 \times 22 \times 3 \times 12CSA=2×22×3×12

→ \sf CSA = 1584CSA=1584

Curved surface area = 1584 m²

\begin{gathered}\boxed{\begin{minipage}{6.2 cm}\bigstar$\:\underline{\textbf{Formulae Related to Cylinder :}}\\\\\sf {\textcircled{\footnotesize\textsf{1}}} \:Area\:of\:Base\:and\:top =\pi r^2 \\\\ \sf {\textcircled{\footnotesize\textsf{2}}} \:\:Curved \: Surface \: Area =2 \pi rh\\\\\sf{\textcircled{\footnotesize\textsf{3}}} \:\:Total \: Surface \: Area = 2 \pi r(h + r)\\ \\{\textcircled{\footnotesize\textsf{4}}} \: \:Volume=\pi r^2h\end{minipage}}\end{gathered}