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Two cones formed from two circular sectors 2018-11-30
The central angles of two sector of a circle are 60 and 120 . Using these sectors two cones are made. If the radius of the smaller cone is 5 cm, find the radius and base area of the larger cone.
Answered by Penny Nom.
Paving stones area 2018-08-08
From Declan:
I am thinking of buying some reclaimed block paving stones. There are 750 pieces in total.
60% are L- 140mm x W -140mm x H-50mm
40% are L-170mm x W-140mm x H-50mm How much area will this cover?

Answered by Penny Nom.
A two digit number 2015-08-21
From Cameron:
Write the 2 digit number that matches the clues.

My number has a tens digit that is 8 more than the ones digit. Zero is not one of my digits.

My number is ________.

Answered by Penny Nom.
Filling three holes with stones 2014-08-20
From mark:
how many tonnes of hardcore/crushed stone would it take to fill 1 hole 9ft diameter 5ft deep and 2 holes both 3ft diameter and 5ft deep
Answered by Penny Nom.
Two cones 2014-04-09
From c.j:
what is the length of the radius of the LARGER cone(the LARGER cone has a slant height of 15) when the SMALLER cone has a radius of 8 and a slant height of 12ft ,please help.
Answered by Penny Nom.
Cones, pyramids, cylinders and prisms 2012-09-13
From Roy:
I read on this page that a pyramid is a special kind of cone, but a cone is not a pyramid. Does this apply to cylinders. Is a prism a special kind of cylinder, but a cylinder is not a prism?
Answered by Robert Dawson.
Two conical tanks 2011-02-17
From rustom:
Two vertical conical tanks (both inverted) have their vertices connected by a short horizontal pipe. One tank, initially full of water, has an altitude of 6 ft. and a diameter of base 7 ft. The other tank, initially empty, has an altitude of 9 ft., and a diameter of base 8 ft. If the water is allowed to flow through the connecting pipe, find the level to which the water will ultimately rise in the empty tank (Neglect the water in the pipe.)
Answered by Penny Nom.
How long will you and your friend be able to talk? 2010-11-23
From beket:
you and your friend leave your home town at the same time your friend travels by train 45 mph directly east while you travel by train 50 mph going directly south you are talking on cell phone but you plan charges extra if the phones are 100 miles apart. How long will you and your friend be able to talk before the charges increase?
Answered by Penny Nom.
The cube of an integer 2010-01-20
From Shankar:
Can the cube of an integer end with 1985 ones ?
Answered by Robert Dawson.
how many ones are in 1 million 2009-09-17
From djuan:
how many ones are in 1 million
Answered by Harley Weston.
Units digit 2008-07-02
From seemachauhan:
How to find unit digit of various numbers and what are unit digits?
Answered by Penny Nom.
The sum of the ones 2007-10-29
From Hangsun:
When 2 two digit numbers are added what is the greatest possible sum of the ones?
Answered by Penny Nom.
Tens and ones 2007-09-16
From julia:
My son has come home with a math question "what i know about 10s and 1s" we're totally stumped any information you can provide would be greatly appreciated
Answered by Harley Weston.
Two cones 2006-12-30
From Cassie:
A cone of radius 6 and height 12 and a different cone of radius 8 and height 12 intersect as shown in the figure below, where the vertex of one matches with the center of the base of the other. Find the volume of the intersection of the two cones (in exact form).
Answered by Penny Nom.
How fast is the water level rising 2006-08-12
From Erin:
Water runs into a conical tank at the rate of 9ft3/min. The tank stands point down and has a height of 10 ft. and a base radius of 5 ft. How fast is the water level rising when the water is 6 ft. deep? (V=1/3 pi r2 h).
Answered by Penny Nom.
Pyramids and cones 2006-06-06
From Melissa:
I was wondering if a cone can be considered a pyramid. Looking at many definitions of pyramids I have read that pyramids come to a common vertex. A cone comes to a vertex. But I also read that pyramids all have triangular faces. In this case a cone would not be considered a pyramid. Am I correct?
Answered by Chris Fisher.
Surface areas 2005-05-11
From Jessica:
How can I demonstrate to my high school students the reason for the formulas for the surface area of a prism, right cylinder, and regular pyramid, and right cone?
Answered by Penny Nom.
Making a cone 2003-12-22
From Tracie:

I am working on a craft project at home and I have been given the following information:
16" tall and 13" diameter at base, with 1 and 1/2 " opening at top.

Is there a basic formula for creating a cone with this info?

Answered by Claude Tardif and Penny Nom.
A sphere inscribed in a cone 2003-08-10
From A student:
A sphere with radius 5cm is inscribed in a right circular cone 20 cm in height.find

(a) the base radius ,volume of the cone
(b)volume of the shaded space( to 3 sig fig)

Answered by Penny Nom.
The vertex of a cone 2003-03-27
From Holly:
I read your response to Callie about whether a cone has a vertex or not. Is it ONLY a vertex if both halves of the cone are together or can one half of the illustration have a vertex?
Answered by Walter Whiteley.
A paper model of a cone 2002-08-14
From Bruce:
I have made a paper model of a cone, cut a sloping section, and removed the top. I have drawn the major and minor axis on the paper surface of the section. The major axis is not symmetrical about the minor axis. To me, this is not an ellipse. To me, an ellipse is a tubular section, because this gives a symmetrical major axis. What is your opinion?
Answered by Walter Whiteley and Chris Fisher.
Conics 2002-05-29
From Brooke:
Which conic cannot be generated by an intersection of a plane and a double napped cone?
Answered by Chris Fisher.
Bicycles and phone calls 2001-02-08
From Sarah:
  1. A bicycle has a diameter of 66 centimeters. How many times must the tire rotate to travel 1 kilometer?explain answer.

  2. Becky want to make a long distance call to her friend Sarah from a pay telephone.She has $5.00 in change.The call costs $0.90 for the first three minutes and $0.24 for each additional minute.How long can Becky talk to Sarah?

Answered by Leeanne Boehm.
Phone Number Possibilities 2000-01-09
From Hamilton Weston:
How do phone companies arrive at the possible number of phone numbers that can be generated for customers?
Answered by Harley Weston.
Nines and ones 1999-11-05
From Greg Miller:
Using the numbers 1, 1, 9, 9, only once each, how can I create an expression that equals 10 using only the basic functions of addition, subtraction, multiplication, division, and/or parentheses?
Answered by Claude Tardif.
Pay Phone Problem 1998-02-26
From Shameq:
Hi, I've been given a problem that I'm having some trouble with. I'd really appreciate any help. Here's the question (it's called the Pay Phone Problem)

A pay phone will take only 10p, 20p, 50p, and 1 coins"(It's British).

A woman has plenty of 10p and 20p coins. She has no other coins. She can put the coins into the pay phone in any order.

INVESTIGATE the number of different ways, she could put the 10p and 20p coins into the pay phone.
Answered by Penny Nom.

Smith, Rodriguez and Jones 1996-11-07
From Rafayel Ambartsumyan:
On a train, Smith, Rodriguez, Jones are the fireman, brakeman, and engineer, but not in that order. Also aboard the train are three businessman who have the same names, a Mr. Smith, a Mr. Rodriguez, and a Mr. Jones. ..... Who is the engineer?
Answered by Penny Nom.



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