Question

sorry previous question was mistake

8. The height of a cone is 15 cm If its volume is 1570 cm cube, find the radius of the base.
(a) 12 cm
(b) 10 cm
(c) 15 cm
(d) 18 cm​

Answer 1

Answer: Option - C

Step-by-step Explanation:

Given,

Height of the cone = 15cm

Volume of cone = 1570cm³

The radius of the base =?

We know that,

The volume of cone = 1/3 πr²h

1/3 πr²h = 1570

1/3 × π × r² × 15 = 1570

πr² × 5 = 1570

=> πr² = 1570/5

=> 3.14 × r² = 314

=> r² = 314/3.14

=> r² = 100

=> r = √100

=> r = 10

Therefore, the radius of the cone is 10cm.

Answer 2

» The height of a cone is 15 cm and its volume is 1570 cm³.

Here ..

• Height (h) = 15 cm

• Volume (V) = 1570 cm³

_____________ [ GIVEN ]

• We have to find the radius (r) of the base.

_______________________________

We know that

› Volume of cone = $\dfrac{1}{3}$πr²h

Put the known values in above formula

=> 1570 = $\dfrac{1}{3}$ × $\dfrac{22}{7}$ × r² × 15

=> 1570 = $\dfrac{22}{7}$ × 5 × r²

=> $\dfrac{1570\:\times\:7}{22\:\times\:5}$ = r²

=> $\dfrac{10990}{110}$ = r²

=> r² = 99.9

=> r² = 100 (approx.)

=> r = √100

=> r = 10

____________________________

Radius of cone (r) = 10 cm

Option b) 10 cm

__________ [ ANSWER ]

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