







The units digit of a square 
20210904 

Aarzu pose la question : Sorry this may be a dumb question but how do you find possible unit digits of a
perfect square Penny Nom lui répond. 





An arithmetic and a geometric sequence 
20210829 

Moti pose la question : Let {an} be an arithmetic sequence such that its 1st, 20th, and 58th terms are
consecutive terms of some geometric sequence. Find the common ratio of the
geometric sequence. Harley Weston lui répond. 





Fibonacci numbers 
20210825 

John pose la question : Make a single column of numbers. Start with two numbers of your choice.
The third number is the sum of the previous two, the fourth number is the sum of
numbers two and three, and so on until
you have ten numbers in the column. Add up all ten numbers. Now, take the
seventh number and multiply it by eleven. This product will equal the sum of the
ten numbers. The same result will occur regardless of the first two numbers
chosen.
The question is why does the 7th number multiplied by 11 always equal the sum of
the ten numbers? Penny Nom lui répond. 





A word problem 
20210728 

Isaac pose la question : The average mass of a group of children is 50 kilograms. Todd, who has a mass of
62 kilograms, then joins the group. This raises the average mass of the group to
52 kilograms. How many children were in the original group Penny Nom lui répond. 





New pool liner 
20210714 

Kareena pose la question : I have a rectangular prism shaped pond that are 4ft by 8ft by 2ft. My pond is
lined on the sides and bottom with a pool liner so that it doesn't leak (the top
of the pool does NOT have a liner). I am redoing my pool and would like to
increase the size of the pond. Each dimension will increase by the same amount,
and the size of the pool liner will double. How much I am increasing each
dimension of the pond? Give an exact answer and than an approx. answer rounded to
the nearest tenth. Penny Nom lui répond. 





How many ways can you travel from A to D? 
20210702 

shawn pose la question : Hello, I am trying to solve a problem which is how many ways can you travel from
A to D. A has 4 options b has 3, C and you get to D. How many ways are there? Penny Nom lui répond. 





3.1 miles in 4 minutes 
20210621 

Jean pose la question : I am a school bus driver. My route directions and time schedule have me traveling
3.1 miles in 4 minutes. How fast do "they" expect me to drive to accomplish this?
Thank You Penny Nom lui répond. 





UFO speed in MPH from nearest galaxy in one year 
20210522 

Joe pose la question : If the next closest galaxy is 15 quadrillion miles away and there are 8760 hours
in one year; how fast would a UFO have to fly to travel from the next
galaxy, in MPH in one year ?
Google calculator gives this result: 1.7123288e+12
I don't understand what the "e+12" means.
How is that pronounced, ex. trillion, quadrillion etc..?
Harley lui répond. 





The diameter of an octagon 
20210522 

Sue pose la question : What is the diameter of an octagon with 8 foot sides Penny Nom lui répond. 





The height of a cone 
20210513 

Carmen pose la question : If a cone has a slant height of 25 inches and a radius of 7 inches what is the
height in inches of the cone? Harley Weston lui répond. 





2.5 percent of 1.5 billion 
20210513 

Anish pose la question : What is the 2.5 percent of 1.5 billion?
please state if there are any general formulae of this calculation.
Thank you Penny Nom lui répond. 





An octagonal drum 
20210511 

Louie pose la question : I teach carpentry on an Indian reservation.
My students want to make an 18 inch drum frame.
They want to have 8 sides or an octagon shape to the drum frame.
What angle I have to set my miter saw to cut the angles to fit the octagon together.
I want to use this formula by changing the diameter of the frame.
Harley Weston lui répond. 





More on a roll of paper 
20210507 

Stephen pose la question : Can you help with the equations to calculate the length of paper required to
achieve a target outside diameter when wrapped around a core please?
The inside diameter of the cardboard core is 76mm
The thickness of the wall of the cardboard core is 5mm
The thickness of the paper is 138microns
The desired outside diameter of the finished roll is 320mm
I hope you can help me with a solution, Thank you Harley Weston lui répond. 





Word problem 
20210507 

Donelle pose la question : Freddy is three times as old as Mary. Mary is twice as old as Jack. Jack is 11
years old. How old is Freddy? Penny Nom lui répond. 





The maximum area of a garden 
20210428 

Lexie pose la question : suppose you want to make a rectangular garden with the perimeter of 24 meters.
What's the greatest the area could be and what are the dimensions? Penny Nom lui répond. 

