If the radii of two spheres are 7 cm and 21 cm and the volume of the bigger sphere is 729 cm^3 . Find the...

If the radii of two spheres are 7 cm and 21 cm and the volume of the bigger sphere is 729 cm^3 . Find the volume of the smaller sphere.

---

The ratio of their radius = 7/21
=1/3
The volume scale factor = (1/3)^3
Hence the volume of the smaller will be
1/27 =x/729
X = 17 cm^3

---

joseph rimiru answered the question on September 30, 2017 at 21:19

Exams With Marking Schemes

• Grade 1
• Grade 2
• Grade 3
• Grade 4
• Grade 5
• Grade 6
• Grade 7
• Grade 8
• Grade 9
• PP1
• PP2
• Playgroup
• Form 1
• Form 2
• Form 3
• Form 4

Related Questions

---

• A rectangle whose area is 36 cm^2 is given an enlargement with linear scale factor of 2.... (Solved)
  

  A rectangle whose area is 36 cm^2 is given an enlargement with linear scale factor of 2. Find the area of the image obtained.

  Date posted: September 30, 2017 .    Answers (1)

• ABCD is a square with A(2,2) and C(5,3) . Find the equation of the diagonal BD (Solved)
  

  ABCD is a square with A(2,2) and C(5,3). Find the equation of the diagonal BD

  Date posted: September 30, 2017 .    Answers (1)

• Find the equation of the line from the point (-1, 4/3) and perpendicular to the line whose equation is ; y-3x+1=0 (Solved)
  

  Find the equation of the line from the point (-1, 4/3) and perpendicular to the line whose equation is; y-3x+1=0

  Date posted: September 30, 2017 .    Answers (1)

• The width of a rectangle is a third of the length. If the perimeter is 96 cm. Find the width (Solved)
  

  The width of a rectangle is a third of the length. If the perimeter is 96 cm. Find the width

  Date posted: September 30, 2017 .    Answers (1)

• Given that x=5/12;find the value of (a).COS X (b).SIN X (c).COS(90-X) (d).SIN(180-X) (Solved)
  

  Given that x=5/12;find the value of (a).COS X (b).SIN X (c).COS(90-X) (d).SIN(180-X)

  Date posted: September 30, 2017 .    Answers (1)

• Find the area of a triangle whose included angle is 30° and the sides being 5 cm and 9 cm. (Solved)
  

  Find the area of a triangle whose included angle is 30⁰ and the sides being 5 cm and 9 cm.

  Date posted: September 29, 2017 .    Answers (1)

• On a map with a scale of 1:500 000, a coffee plantation covers an area of 20 cm^2 . Find the actual area of the... (Solved)
  

  On a map with a scale of 1:500 000, a coffee plantation covers an area of 20 cm^2 . Find the actual area of the plantation I hectares.

  Date posted: September 29, 2017 .    Answers (1)

• The area of a sector of a circle radius 35 cm is 490 cm^2. Calculate the angle subtended at the centre of the circle. (Take... (Solved)
  

  The area of a sector of a circle radius 35 cm is 490 cm^2. Calculate the angle subtended at the centre of the circle. (Take π =22/7 ).

  Date posted: September 29, 2017 .    Answers (1)

• Using the Hero’s formula find the area of a triangle whose sides are 8 cm, 6cm, and 10 cm (Solved)
  

  Using the Hero’s formula find the area of a triangle whose sides are 8 cm, 6cm, and 10 cm

  Date posted: September 29, 2017 .    Answers (1)

• Calculate the surface area of a solid cone of base radius 14 cm and the height 26 cm. (Solved)
  

  Calculate the surface area of a solid cone of base radius 14 cm and the height 26 cm.

  Date posted: September 29, 2017 .    Answers (1)

• A house to be built measure on a plan as 40cm by 20 cm. If the linear scale factor is 25, find the ... (Solved)
  

  A house to be built measure on a plan as 40 cm by 20 cm. If the linear scale factor is 25, find the
  actual area of the house.

  Date posted: September 29, 2017 .    Answers (1)

• Use binomial expansion to evaluate (1.02)^6 to 4 s. f (Solved)
  

  Use binomial expansion to evaluate (1.02)^6 to 4 s. f

  Date posted: September 28, 2017 .    Answers (1)

• Factorize 2a(x - y) + 3b( y - x) . (Solved)
  

  Factorize 2a(x - y) + 3b( y - x) .

  Date posted: September 27, 2017 .    Answers (1)

• s = ut +1/2 at^2 . Find a when s = 6000, u= 10 and t = 20. (Solved)
  

  s = ut +1/2 at^2 . Find a when s = 6000, u= 10 and t = 20.

  Date posted: September 27, 2017 .    Answers (1)

• Evaluate 0.219 x´ 0.257 to 3 significant figures. (Solved)
  

  Evaluate 0.219 x´ 0.257 to 3 significant figure.

  Date posted: September 27, 2017 .    Answers (1)

• If a : b = 3 : 4 and a : c = 2 : 5, find a : b : c. ... (Solved)
  

  If a : b = 3 : 4 and a : c = 2 : 5, find a : b : c.

  Date posted: September 26, 2017 .    Answers (1)

• Find Cos x if Cos 2x = 0.9. (Solved)
  

  Find Cos x if Cos 2x = 0.9.

  Date posted: September 26, 2017 .    Answers (1)

• A car travels 100 km in (¾) hour. How far will it travel in 20 min? (Solved)
  

  A car travels 100 km in (¾) hour. How far will it travel in 20 min?

  Date posted: September 26, 2017 .    Answers (1)

• Using the mathematical tables, find the tangent, sine and cosine of the following angles. a. 52° b.... (Solved)
  

  Using the mathematical tables, find the tangent, sine and cosine of the following angles.
  a. 52⁰ b. 53.50⁰ c. 30⁰ 20’
  

  Date posted: September 26, 2017 .    Answers (1)

• Akinyi bought and beans from a wholesaler. She then mixed the maize and beans the ratio 4:3 she brought the maize as Kshs. 12 per kg... (Solved)
  

  Akinyi bought and beans from a wholesaler. She then mixed the maize and beans the ratio 4:3
  she brought the maize as Kshs. 12 per kg and the beans 4 per kg. If she was to make a profit of
  30% what should be the selling price of 1 kg of the mixture

  Date posted: September 25, 2017 .    Answers (1)