Question

पुस्तक में लिखित ₹5000 की बुक पुरानी मशीन ₹4500 में बेचा​

Answer 1

Answer:

Given:

The circumference of the base of cylinder is 30.8cm.

Its curved surface area is 289.52 cm ²

To Find:

Height of cylinder

Solution:

Using formula:

$\red{ \underline {\boxed{ \rm {\pmb {Circumference \:  of \:  cylinder {=  2πr }}}}}}  \: \star$

$~$

$\red{\underline { \boxed{ \rm { \pmb{CSA  \: of  \: cylinder = 2\pi rh }}}}}  \: \star$

Circumference of cylinder = 30.8 cm

$\sf \mapsto2πr = 30.8 cm$

$\sf \mapsto2 ×  \dfrac{22}{7}  × r =  \dfrac{308}{10}$

$\sf \mapsto \: 44 \times 10 \times r = 308 \times 7$

$\sf \mapsto440 \times r = 2156$

$\sf \mapsto r =  \dfrac{2156}{440}$

$\pmb{ \boxed{ \sf{ \mapsto  {r = 4.9cm}}}}  \:  \pink  \star$

$~$

Now,

CSA of cylinder= 2πrh

$\sf \mapsto289.52 = 2 \times  \dfrac{22}{7}  \times  \times 4.9 \times h$

$\sf \mapsto \dfrac{28952}{100}  = 2 \times  \dfrac{22}{7}  \times  \dfrac{49}{10}  \times h$

$\sf \mapsto   \dfrac{28952}{100}   = \dfrac{44 \times 49}{7 \times 10}  \times h$

$\sf \mapsto \dfrac{28952}{100}  =  \dfrac{2156}{70}  \times h$

$\sf \mapsto h =  \dfrac{28952 \times 70}{2156 \times 100}$

$\sf \mapsto \dfrac{ \cancel{2026640}}{  \cancel{215600}}$

$\boxed{ \pmb{ \sf \mapsto h  = 9.4cm}}  \:  \pink\star$

$~$

Hence,

Height of cylinder is 9.4cm

Explanation: