math

A number of circles touch each ather. The area of the smallest circle is 4picm2 and each consecutive circle has area 9/4 times that of the previous one. If the distance AB=665/8. Line AB passes at the centre of the circles. How many circles are there?

  1. 👍 0
  2. 👎 0
  3. 👁 89
asked by jay
  1. The smallest circle has a radius of 2.
    Each circle's radius is 3/2 that of the previous one.

    If there are n circles, then since the first and last circles are only traversed halfway, we have

    2 + 4(3/2) + 4(3/2)^2 + ... + 2(3/2)^(n-1) = 665/8

    Hmmm. I get a non-integer solution for n.

    Below are the lengths of AB as the number of circles increases
    2
    4*3/2 = 6; 2+6 = 8
    6*3/2 = 9; 8+9 = 17
    9 * 3/2 = 27/2; 17 + 27/2 = 61/2
    and so on.

    Have I misread something?

    1. 👍 0
    2. 👎 0
    posted by Steve
  2. it saids 423+5123

    1. 👍 0
    2. 👎 0
    posted by kylie

Respond to this Question

First Name

Your Response

Similar Questions

  1. math

    A number of circles touch each ather. The area of the smallest circle is 4picm2 and each consecutive circle has area 9/4 times that of the previous one. If the distance AB=665/8. Line AB passes at the centre of the circles. How

    asked by jay on March 3, 2015
  2. math

    A number of circles touch each ather. The area of the smallest circle is 4picm2 and each consecutive circle has area 9/4 times that of the previous one. If the distance AB=665/8. Line AB passes at the centre of the circles. How

    asked by jay on March 4, 2015
  3. math

    A number of circles touch each ather. The area of the smallest circle is 4n cm^2 and each consecutive circle has area 9/4 times that of the previous one. If the distance AB=665/8. Line AB passes at the centre of the circles. How

    asked by kamo on March 4, 2015
  4. maths

    A number of circles touch each ather. The area of the smallest circle is 4n cm^2 and each consecutive circle has area 9/4 times that of the previous one. If the distance AB=665/8. Line AB passes at the centre of the circles. How

    asked by jay on March 3, 2015
  5. mathematics,physics,life science,LO,afrikaans

    A number of circles are given and the area of the smallest circles is 4π.The area of the next circle is 9/4 times of the previous circle.if there are 6 circles,determine the length of the diameter of the last circle.

    asked by uchriciah on March 8, 2015
  6. GEOMETRY

    Two circles with radii a and b touch each other externally . Let c be the radius of a circle which touches these two circles as well as their common tangent to the two circles . Then relate a,b and c through an equation

    asked by PRANAV on March 15, 2015
  7. Maths

    Three circles of radius 1 unit fit inside a square such that the two outer circles touch the middle circle and the sides of the square. Given the centres of the circle lie on the diagonal of the square, find the exact area of the

    asked by Lilly on February 19, 2017
  8. GEOMETRY(CIRCLE)

    Three circles with different radii have their centers on a line. The two smaller circles are inside the largest circle, and each circle is tangent to the other two. The radius of the largest circle is 10 meters. Together the area

    asked by i need help from anyone! on March 25, 2013
  9. geometry

    Theres a circle with an equilateral triangle in the middle. The traingles edges all touch the circle. The radius of the circle is 8 meters. How do I find the area of the triangle? Sorry The triangles edges don't touch the circle,

    asked by Emily on April 4, 2007
  10. Maths

    the figure below shows 3 similar circles that just touch one another.A,Band C are the centres of the circles.If the perimeter of the triangle ABC is 42cm, what is the total area of the unshaded part of the 3 circles. (take pie =

    asked by Jeannie on April 24, 2013

More Similar Questions