Question
A solid metallic sphere of radius 15 cm is melted and
recast into spherical balls of radius 3 cm each. What is the ratio of the surface area of the original sphere and the sum of the surface areas of all the balls?Solution
Let the number of the smaller sphere be 'x' Volume of the bigger sphere = x × (volume of the smaller sphere) (4/3)π 15^3 = x × (4/3)π 3^3 x = 125 So their are total 125 smaller spheres Now, The surface area of the larger sphere = 4π 15 ⇒ 900π Surface area of smaller sphere = 4π 3^2 ⇒ 36π Total surface area of 125 smaller spheres = 125 × 36π ⇒ 4500π Surface area of the bigger sphere : Surface area of all smaller spheres = 900π : 4500π ⇒ 1 : 5
In each of the following questions, choose that set numbers from the four alternative sets, that is similar to the given set.
Given set:Â [92...
‘Spinach’ is related to ‘Herb’, in the same way as ‘Mango’ is related to ‘____’.
(The word must be considered as meaningful Englis...Select the option that is related to the first number in the same way as the third number is related to fourth number and the fifth number is related to...
In a certain code language, ‘plant is life’ is written as ‘ni vi di, ‘get me plant’ is written as ‘hi di ri’, and ‘get is tree’ is wri...
- Select the option that is related to the third term in the same way as the second term is related to the first term and the sixth term is related to the fi...
Select the option that is NOT like the given set.
(8, 40, 56)
WORD : 3584 :: PLAN : 6214 :: CODE : ?
Select the option that is related to first number in the same way third number is related to forth number.
26: ? :: 34: 1224
65 : 31 :: 72 : ? :: 34 : 13
Hard : Stone :: Soft : ?