MHB Marbles & Stamps: How Many Did Casey Buy?

  • Thread starter Thread starter wailingkoh
  • Start date Start date
  • Tags Tags
    Marble
AI Thread Summary
Carey initially bought marbles and gave half to Casey, who then purchased stamps and shared half back with Carey. After Carey used 5 stamps and Casey gave away 11 marbles, the remaining ratios of stamps to marbles for both individuals were established. Specifically, the ratio for Carey was 1:7, while for Casey it was 1:5. The discussion revolves around determining the number of stamps Casey originally bought based on these ratios and the transactions. The problem invites participants to share their attempts or difficulties in solving it.
wailingkoh
Messages
18
Reaction score
0
I have a question

Carey bought some marbles and gave half of them to Casey. Casey bought some stamps and gave half of them to Carey. Carey used 5 stamps and Casey gave away 11 marbles. The ratio of the number of stamps to the number of marbles Carey had left then became 1 : 7 and the ratio of the number of stamps to the number of marbles Casey had left became 1 : 5. How many stamps did Casey buy?
 
Mathematics news on Phys.org
So what is the problem? Have you tried anything? Post your attempt (or at least something which explains your difficulty in solving the question).
 
Seemingly by some mathematical coincidence, a hexagon of sides 2,2,7,7, 11, and 11 can be inscribed in a circle of radius 7. The other day I saw a math problem on line, which they said came from a Polish Olympiad, where you compute the length x of the 3rd side which is the same as the radius, so that the sides of length 2,x, and 11 are inscribed on the arc of a semi-circle. The law of cosines applied twice gives the answer for x of exactly 7, but the arithmetic is so complex that the...
Thread 'Video on imaginary numbers and some queries'
Hi, I was watching the following video. I found some points confusing. Could you please help me to understand the gaps? Thanks, in advance! Question 1: Around 4:22, the video says the following. So for those mathematicians, negative numbers didn't exist. You could subtract, that is find the difference between two positive quantities, but you couldn't have a negative answer or negative coefficients. Mathematicians were so averse to negative numbers that there was no single quadratic...
Thread 'Unit Circle Double Angle Derivations'
Here I made a terrible mistake of assuming this to be an equilateral triangle and set 2sinx=1 => x=pi/6. Although this did derive the double angle formulas it also led into a terrible mess trying to find all the combinations of sides. I must have been tired and just assumed 6x=180 and 2sinx=1. By that time, I was so mindset that I nearly scolded a person for even saying 90-x. I wonder if this is a case of biased observation that seeks to dis credit me like Jesus of Nazareth since in reality...
Back
Top