







Surface area of a hemisphere 
20171028 

From Shaina: If the total surface area of a hemisphere be 36.22/7 cm then its radius will be 3 cm is it true or false Answered by Penny Nom. 





Adding fractions 
20171027 

From Sandy: virinchi distributed 4/7 of cake to his friends 1/3 of it to his family members which part of cake is remaining? Answered by Penny Nom. 





f(x)=x^26x find f(x2) 
20171027 

From Kenneth: f(x)=x^26x find f(x2) Answered by Penny Nom. 





Solve 2cos^2 x + sin x = 2 
20171025 

From Yamama:
hello ! I need help to solve this equation :
2cos^2 x + sin x = 2
Thank you very much
Regards Answered by Penny Nom. 





11% of a central angle 
20171022 

From Hope: How do you turn a percentage in to a central angle eg. 11% Answered by Penny Nom. 





A tangent to a curve 
20171022 

From Jasem:
Suppose that
f(x)=(3x3)^1/2.
(A) Find an equation for the tangent line to the graph of f(x) at x=2
(B) Find all values of xx where the tangent line is horizontal, and enter them as a commaseparated list (e.g., 2,3,6). If there are none, enter none.
Values of x Answered by Penny Nom. 





Sampling distribution 
20171016 

From Esther: I need 4digits combination of 235689 and without replacement. Thanks Answered by Penny Nom. 





Salary plus commission 
20171016 

From Natasha: Veronika works at Future Shop and earns ₱10.50/h plus 6% commission on sales. Last week Veronika worked 40 hours. What was Veronika’s weekly gross salary if her total sales were ₱2050? Answered by Penny Nom. 





The distance between the origin and a moving point on a graph 
20171016 

From Paulina: Find the rate of change of the distance between the origin and a moving point on the graph of y=x^2 +1 if dx/dt=2 centimeters per second Answered by Penny Nom. 





Three consecutive odd integers 
20171010 

From Johanna: Three consecutive odd integers are such that the sum of the first and second is 31 less than 3 times the third Answered by Penny Nom. 





27000001 
20171009 

From Tulashiram: If a× b =27000001, then what is the value of a & b ? Answered by Penny Nom. 





Five bales 
20171008 

From John:
two answers were given... I believe both to be incorrect.
five bales weighed two at a time: weightx2 given: 110,112,113,114,115,116,117,118,120, and 121. It stated all combinations ie: ab,ac,ad,ad,bc,bd,be, etc. to arrive at the above 10 combined weights. I come up with the following...
Bale A= 54lbs, Bale B=56, Bale C=58, Bale D=59. and Bale E=62 pounds.
A+B=110, A+C=112, A+D=, B+C=114, B+D=115 ,A+E=116 ,C+D=117, B+E=118 ,C+E=120, and D+E=121 Answered by Penny Nom. 





An enclosure for some remote control boats 
20171003 

From Roberto: I am trying to build a "ring" for our remote control boats, using irrigation pipe.
I'd like to use full 20' long sticks for the long sides and use eight of what we call
45s, which are actually 135' fittings to make the six short sides. If I know the length
of the two long sides, what would be the formula to find the exact lengths of the short sides?
Thank you. Answered by Penny Nom. 





The volume of a cone without calculus 
20171002 

From Akash: How to find the volume of a cone without the knowledge of calculus? Answered by Penny Nom. 





The square root of 6 is irrational 
20171002 

From John: http://mathcentral.uregina.ca/QQ/database/QQ.09.06/sylvia1.html
In the initial assumption of that proof, root 6 is assumed to be a/b where a and b have no common factors, but why does having a common factor make it irrational? Answered by Penny Nom. 

