







A cone formed from a circular sector 
20180418 

From Jessica: A circle has a radius of 7.5cm. A sector with an angle of 240 degrees is cut out from the sector. If the sector is folded to form a cone. Find the length of the cone. Answered by Penny Nom. 





Pool Digit Combinations 
20180418 

From Jacob: I need to know all the possible 3 digit combinations from the following pool of digits: 1st pool (1,2,3), 2nd pool (4,5) and the 3rd pool (7,8,9,0). Each pool has to be represented in the combinations.
The numbers can be repeated as long as they are not of the same set.
Example for not repeating: 123 is ok but not 321 or 231,132,213, etc.
The question is somehow related to Mike's but the difference is the digits are allocated into pools. Your help can assist me solve a mystery. Thanks. Answered by Penny Nom. 





A circle inscribed in a quarter circle 
20180416 

From abhijeet: ABC is a quarter circle and a smaller circle is inscribed in it. if AB = 1cm then find the radius of smaller circle Answered by Penny Nom. 





A triangle in a cube 
20180416 

From Sohel: A cube has an edge of 4 cm. A triangle is formed by joining the middle point of one face of the cube to the ends of a diagonal of the opposite face . What will be the area of the triangle ? Answered by Penny Nom. 





What is small fourdigit whole number? 
20180415 

From Rajesh: What is small fourdigit whole number? Answered by Penny Nom. 





The angles of a trapezoid 
20180414 

From Gautham: In trapezoid ABCD, sides AB and CD are parallel, \angle A = 2angle D, and angle C = 3angle B. Find angle A. Answered by Penny Nom. 





The mass of a durian 
20180414 

From REEVASSHINIE: A watermelon with a mass of 5 kg and two durians with the same
mass are placed on an electronic balance.If the reading shown on the
balance is m kg,write an expression for the mass of a durian Answered by Penny Nom. 





The length of a diagonal of a box 
20180413 

From Valentina: A packaging box for a metal rod is 7.5 inches along a diagonal of the base the height of the box is 18 inches what is the lengh of a diagonal of the box? Answered by Penny Nom. 





Covering a region with mulch 
20180413 

From Roberta: I have a fall zone area of approx. 700 sq ft. that I have to cover with a 6in depth of mulch. How much mulch would I need to purchase? Answered by Penny Nom. 





Division and remainders 
20180412 

From Yogendra: A number is divided by 5,7 and 9. Reminder are 1,2 and 3 respectively.
What is the number?. Give suitable calculations. Answered by Penny Nom. 





Graham's money box 
20180412 

From Tasnim: Graham's money box consists of sh.10 and sh.5 coins. There are 24 coins and it's total value is 150. Find how many of each coins are there in the box Answered by Penny Nom. 





The sides of a circle 
20180410 

From Reid: Hello,
I recently was wondering about whether or not a circle has an infinite number of sides, and I ended up searching it on your website. I saw that you guys found the question to be too ambiguous or something of that nature, and I thought about your process of reasoning involving vertices and such. I soon realized that I may have come up with the solution to the question, but I want to confirm it with you guys. Allow me to explain:
A circle, unlike any other typical 2 dimensional polygon, can sustain an infinite number of straight lines coming in contact with only one point on it. A square, for example, cannot. A square only has 4 locations that can sustain a such a line, each of those being its corners. The flat edge of a square cannot support a tangential line, because the line would either be crossing the edge of the square or coming into contact with multiple points along its edge.
This concept is consistent in every 2 dimensional polygon: pentagons sustain 5 locations for tangential lines, hexagons 6, nonagons 9, etc.
The reason a circle has an infinite number of sides is simply the fact that it must have an infinite number of "corners", assuming it can be defined as a polygon like any of the shapes I described above.
Corners can only exist assuming there is two sides coming into contact with one another.
If there is an infinite number of corners in the circle, which is apparent due to the above reasoning, there must be an infinite number of sides coming into contact with each other.
Thus, a circle is a polygon that consists of an infinite number of sides coming into contact with each other.
Please review this reasoning and let me know if it is solid.
Thank you! Answered by Penny Nom. 





Rolling 2 dice 
20180406 

From Jose: Find the probability p that the sum is as stated when a pair of dice is rolled.
(a) Even and doubles.
p=
(b) Even or doubles.
p= Answered by Penny Nom. 





A side of a square 
20180406 

From Angie: I am dyslexic and have problems with spelling and math I'm trying to figure 4.610 Acres Square trying to figure out how many feet or yards of one side if that makes sense to you thank you I'd really appreciate the help Answered by Penny Nom. 





Factoring a quadratic 
20180402 

From Billy: I need help factoring the following question:
4x(squared) 10x +16. Answered by Penny Nom. 

