In a trading card game, you can trade 6 red cards for a blue card, and a free red card. A man saves up and buys a pack of 72 red cards. How many blue cards can he get?
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
Extension: let n be the number of red cards he has. If he can trade them all for blue cards with no red cards remaining, then find a classification of n .
Log in to reply
Could work nicely as a problem. Post it!
suppose first set of blue cards = n/6 so the no of free red cards obtained will also be n/6 ... so the second set of blues = n/36 ...then n/216 and so on... so now we have series of tetms in a geometrical progression sych that the last last term = 0( since no red cards are left)...let this last term be T
n/6 , n/36, n/216.......(T-2)th term, (T-1)th term, 0
then T= (n/6) (1/6)^{T-1}=0 since last term is 0 we get the value of T in terms of n...
to get the total blue cards we add all T terms of the series using integration /summation...it will be an even no
i didn't take calculus course so anyone who is comfortable with it pls proceed fwd and find out the final solution...
Hey Matthew!!!
14 blue cards and 2 red cards
Trading 6 red cards for a blue card & extra red card is essentially trading 5 red cards for a blue card. With a 72-card deck you can trade for 14 blue cards, with 2 reds left over. 72/5 = 14 & 2/5.
So think of it like this: There are 72 red cards and if you trade 6 reds, you get a blue card and a red card back. So, if you dived 72 by 6, you get 12. So that's 12 blue cards. However, for every 6 red cards, you got 1 blue, and 1 red card, so you still have 12 red cards. What's 12 divided by 6? 2. So that's 2 more blue cards. If you add them up, 12+2, you get a total of 14 blue cards. Hope this helps!
~ =^.^=
Ok so I said if I get a 're card back I'm really only giving 5 red for one blue so 72 ÷5=14.4 he can only get 14 cards. Y'all make it so difficult lol
6 7 2 + 6 2 7 2 = 6 7 2 + 3 6 7 2 = 1 2 + 2 = 1 4 .
72 red cards gives 72/6= 12 blue cards and 12 red cards so that 12 red cards gives 2 blue cards and 2 red cards so finally he will get 12+2= 14 blue cards and 2 red cards
red cards = r
blue cards = b
while r>6....
6r = r+b
72 = 6r
r1 = 12
b = 12 also, but this doesn't matter in the context of the problem.
if r>6, the problem has to go through another iteration.
12 = 6r
r2 = 2
since r !> 6, the problem can be solved now.
r1+r2 = rt
12+2 = 14
Thus, 14 is the answer.
(Longwinded, I know. Sorry.)
When ever he is giving 6 cards.. He will get back one among that...so we can assume for 5 red cards he will get an blue card...so 72/5 =14 where he has two red cards remaining
You can get 1 blue and 1 free red card instead of 6 red cards. So, we can say that we can get 1 blue card for 5 red cards(6 red cards - 1 free card). Thus, we can get 14 blue cards(72÷5). 2 is the remainder in 72÷5 which means we have 2 red card also. So, finally we have 14 blue cards and 2 red cards.
Problem Loading...
Note Loading...
Set Loading...
The man buys a pack of 72 cards. When he trades these he will get 12 blue cards and 12 red cards. And from those extra red cards he can get two additional blue cards, a total of 14 blue cards, and 2 red cards.