Question

plz solve the question???

Answer 1

Volume :- 12308.8 cm³

Top radius ( r1 ) = 20cm

Bottom radius ( r2 ) = 12cm

Volume of frustum =

$\frac{1}{3} \pi \: h ( {(r1)}^{2} + ( {r2)}^{2} + r1r2)$

$12308.8 = \frac{1}{3} \pi \: h \: (400 + 144 + 240)$

36926.4 = πh ( 784 )

$36926.4 = \frac{22}{7} \times 784h$

36926.4 = 112 × 22 h

14.9 = h


Slant height ( l )

$l \: = \sqrt{ {(r1 - r2)}^{2} + {h}^{2} }$

$l = \sqrt{ {(20 - 12)}^{2} + 222.01 }$

l = √( 64 + 222.01 )

l = √286.01

l ≈ 16.9



CSA + πr² = Total area of metal

πl ( r1 + r2 ) + π ( r2 )²

π ( 16 . 9 × 32 + 144 )

π ( 540.8 + 144 )

π 684.8

2152.2 cm² = metal sheet required.



Cost :-

rs 10 ------ 50 cm²

rs 1/5 -------1 cm²


2152.2 cm² ----- rs 430.44