







A fraction 
20180502 

From Adwin: The denominator of a rational number is greater than its numerator by 8. If the numerator is increased by 17 the number obtained is 3 by 2. Find the number. Answered by Penny Nom. 





Gauss' Addition of whole numbers. 
20180430 

From Brad: I found this on your site. Question: what is the sum of the first 100 whole numbers??
Is there a different formula if the numbers begin at a number other than one? For example
What is the series I want to add is goes from 7  53? Answered by Harley Weston. 





Spreading soil over 10 acres 
20180429 

From Joe: If you have 54000 cubic yards of soil and want to spread it over 10 acres of land, by how many inches would the ground level rise? Answered by Penny Nom. 





The weight of a cylinder 
20180427 

From Jared: What is the formula for the weight of a cylinder (not hollow) made of cast iron if it has a height of 5.25 inches and a diameter of 1.75 inches? Answered by Penny Nom. 





Throwing a football 
20180426 

From Abby: Daring Danny's threw a football at an angle of 40 degrees to the horizontal. The football hit the ground at 36 feet. Danny is 5 feet 1 inch tall. Find the initial velocity
I have been trying to figure this problem out for forever! Please help! I am really confused because I don't know time either and you are supposed to find that as well as velocity. Answered by Penny Nom. 





A rectangular prism with rounded corners 
20180425 

From Jackie: Rectangular prism that is 40 by 20 with rounded corners with a radius of 2.5.
What would the surface area be? Answered by Penny Nom. 





More on the curvature of the Earth 
20180423 

From will: the formula for figuring the earth's curve goes against logic, looking at a fixed point and backup 1mi. the point drops 8" then 16" in the next mi. and 32" in the third mi. why shouldn't it be 24" why is the 8" per mi. squared can you tell me in laymens terms why this is it goes against logic it would seem the correct wat would be to add up 8" per mile as you back up from the fixed point 8" 16" 24" 32" not 8/16/32/64" Answered by Harley Weston. 





Seven tangent circles 
20180423 

From Domenick: How to calculate the circumscribed and inscribed circles formed by seven .019685 diameter circles arranged in a circle with all seven circles tangent to each other? Answered by Penny Nom. 





A volume expression for a pyramid 
20180423 

From Shaheer: Do a three sided pyramid and a square pyramid have the same formula if you want to calculate the volume? Answered by Penny Nom. 





The distance between two men 
20180421 

From Kristin: If a 5 ft 6 in man gets hit at a downward 45 degree angle by a 5 ft 10 in man, how far apart are the two men? AND, would the shorter man have to be kneeling or standing? Is there a formula and answer for this question? Answered by Penny Nom. 





Nickels, dimes, and quarters 
20180420 

From Patti: A copy machine accepts nickels, dimes, and quarters. After 1 hour, there are 30 coins total, and their value is $5.10. How many nickels, quarters, and dimes are in the machine? (Hint: There are exactly five different solutions.) Answered by Penny Nom. 





How to find the area of triangle? 
20180419 

From g.a: how to find the area of triangle Answered by Penny Nom. 





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. 

