







A 4 digit combination lock 
20190202 

From Brijanshu: I have a lock that contain only four no. 6,7,8 & 9 . How many possible password of four digit containing these Number. Answered by Penny Nom. 





A lost iPhone pass code 
20170417 

From Sam: I have a locked iPhone and it has all my of my holiday photos on it. I changed the password and then I think I did a incorrect number pattern but anyway I know it ends with 99 and the first 4 digits are 235 and 6 could you please send all of the combinations for this password (without the 99) Thx and plz get back ASAP I need it for school Answered by Penny Nom. 





The sweep angle of a video camera 
20151125 

From Franc: a television camera is 30ft from the sideline of a basketball court 94 ft long. The camera is located 7 ft from the mid court. through what angle must it sweep in order to cover all action on the court? Answered by Penny Nom. 





Seven switches with 3 stages each 
20150915 

From jeff: We are trying to solve a combination problem. If I have 7 things that can be in 3 states (say on/partially on/off), and all 7 have to a state. How many different combinations can there be? It doesn't seem like we should treat it as 21 independent things, but not sure how to break the problem apart. Answered by Penny Nom. 





Sixdigit passwords 
20130319 

From Judy: Hello:
Can you please explain why the answer to the following question is 10^6?
What is the number of possible sixdigit passwords when using the digits 0 through 9, with repetition allowed.
Thank you. Answered by Penny Nom. 





Two swimmers 
20121022 

From Emily: Two swimmers start from opposite sides of the pool. Each swimmer swims the length of the pool and back at a constant rate. They pass each other for the first time 40 feet from one side of the pool and for the second time 45 feet from the other side of the pool. What is the length of the pool? Answered by Penny Nom. 





New Brunswick hst 
20110325 

From andy: what is the short formula to get the hst 13% out of the total price of an item Answered by Penny Nom. 





Tiling a swimming pool 
20110109 

From rustom: (a) Find the volume of water in swimming pool with vertical ends and sides
. The length measured at the water line is 50 ft. and the breadth is 20 ft. The
bottom of the swimming pool is a plane sloping gradually downward so that
the depth of the water at one end is 4 ft. and 8ft. at the other end.
(b) If the sides, ends, and bottom of the swimming pool are constructed of
tile blocks whose glaze surface dimensions are 3in by 6in. , and if the ends
and sides of the pool extend 2ft.above the water level, find the number of
blocks used if 1/20 of the surface area is covered by sealing material.
I got the (a) question but I don't know the (b) question which have the answer
of 16,136 blocks. I hope I can get the procedure for this, THANK YOU! Answered by Penny Nom. 





30,000 US gallons of water 
20101012 

From mike: If a swimming pool can hold 30,000 US gallons of water  is it possible to calculate the number of yards of dirt it would take to fill the hole? Answered by Penny Nom. 





A Lagoon, free form, inground swimming pool 
20091222 

From donna: What is the linear footage of a 14 x 23, Lagoon, free form, inground swimming pool? Answered by Robert Dawson. 





Passwords 
20090708 

From Tim: pretend I have a password that is  9k7d4112p5o
assuming that you continuously guessed wrong until that exact
combination was the only possible answer left;
how many times would you have to guess?
capital letters are not relevant
and you do not know how many digits there are Answered by Stephen La Rocque. 





A rectangular open box 
20090321 

From tina: An open box is to be made from a rectangular piece of tin by cutting two inches squares out of the corners and folding up the sides. The volume of the box will be 100 cubic inches. Find the dimensions of the rectangular piece of tin. Answered by Stephen La Rocque. 





The weight of water in a swimming pool 
20090310 

From ely: How much does the water in a swimming pool 20 ft long, 10 ft wide, and 6 ft deep weigh? Answered by Penny Nom. 





The nth term of a sequence 
20080913 

From lavett: what is the Nth term in the sequence when the sequence is 2,4,8,16... and the term numbers are 1,2,3,4... Answered by Stephen La Rocque. 





The volume of a swimming pool 
20080810 

From Ron: What is the volume of a swimming pool when its length is 40 ft, width 20ft, the deep end is 10 ft and the shallow end is 3 ft.? Answered by Penny Nom. 





The amount of water in a pool 
20080330 

From anurag: what will the weight of water in a swimming pool having dimensions of 18ft *10ft*5 ft?
how much water will be needed for filling it up? Answered by Penny Nom. 





2 password policies 
20071017 

From Larry: 2 password policies are in question.
Policy 1 states that a password must be between 6 and 8 characters
Policy 2 states that that a password must be exactly 8 characters.
Both policies state that Passwords can contain AZ az 09 (26*2)+ 10 characters to choose from.
Which policy is stronger?
How many potential passwords exist for policy 1 and how many for policy 2? Answered by Penny Nom. 





Filling an old swimming pool 
20070827 

From Russ: I would like to know how much fill material I would need to fill an old swimming pool. The pool is 18' wide x 36' long and is 4' to 10' deep. Answered by Penny Nom. 





The swaying of a building in the wind 
20070811 

From San: During a strong wind, a tall builing, such as the CN Tower, can sway
back and forth as much as 100cm, with a period of 10 seconds.
Please help me to determine the equation for this function, in the form
y=asinkx Answered by Stephen La Rocque. 





Swimming pool water 
20070412 

From tina: How much water does a 24' round, 4' deep swimming pool hold? Answered by Haley Ess. 





Nine character passwords 
20070327 

From oliver: suppose a password consisted of a string of nine characters from the
english alphabet(26 characters). if each possible password could be tested
in a microsecond,how long would it take to test all possible passwords? Answered by Penny Nom. 





Find the total distance the swing traveled before it stopped. 
20061217 

From Leah: Rebecca's little sister liked for her to push her in the swing at the park. The other day Rebecca pulled the swing back and let it go. She would have kept pushing, but she suddenly saw a friend at the other end of the park. The swing traveled a total distance of 10 feet before heading back the other way. Each swing afterwards was only 80% as long as the previous one. Find the total distance the swing traveled before it stopped. Answered by Penny Nom. 





Litres of water in my swimming pool 
20060816 

From A student: I need to calculate how many litres in my swiming pool, it is a circle shape, 5.5 m in diametre by 1.07 m deep. Answered by Stephen La Rocque. 





Quadratics and quintics 
20060718 

From Lynne: What is wrong with this statement? "The quintic is one step up from the dread quadratic equation." (Newsweek, Dec. 19, 2005) Answered by Stephen La Rocque. 





How many gallons of water are in a 24' X 4' round swimming pool? 
20060615 

From Nicole: How many gallons of water are in a 24' X 4' round swimming pool? Answered by Stephen La Rocque. 





At what rate is the circumference of the circle increasing? 
20050808 

From John:
A mathematics professor is knitting a sweater. The main part of the sweater is knit in a large spiral, ending up with a diameter of 30 inches. She knits at a constant rate of 6/7 square inches per minute.
1. At what rate is the circumference of the circle increasing when the diameter is 2 inches?
2. How long will it take her to finish this piece of the sweater?
Answered by Penny Nom. 





Crossword math puzzle 
20040914 

From Joyce and Tiffany: The puzzle name was real number vocabulary and the question is (a number that divides evenly into another what is it?). (Space in between ticmarks on a number line). Answered by Harley Weston. 





A quadratic word problem 
20040204 

From Carl: A walkway of uniform has 72m2 and surrounds a swimming pool that is 8m wide and 10m long. Find the width of the walkway. Answered by Penny Nom. 





Filling A swimming pool 
20021121 

From Sarah: A swimming pool is being filled by three pumps. Alone pump A would take 6 hours, pump B would take 3 hours, and pump C would take 3 hours. If all three pumps are used to fill the pool, what fraction of the process is pump A. Answered by Penny Nom. 





Compass points 
20021105 

From Mhairi: I was asked this in maths but I am not sure if it is geography. Name all the compass points? We have been given 8 but he told us there is more and we have to name them. Answered by Chris Fisher. 





Minesweeper 
20011024 

From Un eleve: J'espere que vous pourrez m'aider. Est ce que vous connaissez un algorithme ou une strategie de resoulutiom pour le jeu du demineur (8x8 avec 10 mines)(Minesweeper). Answered by Claude Tardif. 

