Jacob has a piece of toast that has butter on one side, and he dropped it twice. ....

Question

anonymous · Answer

Jacob has a piece of toast that has butter on one side, and he dropped it twice. Both times it landed with the butter side up. If he drops it two more times, what is the probability that it will have landed butter side up a total of three times? 

 one over four 

 one over two 

 one over three 

 two over three

anonymous · Answer

I would say 1/2

anonymous · Answer

How do you know? Can you say the steps plz?:)

geerky42 · Answer

Think of toast as coin. it already landed side up twice, so two times so far. And then Jacob decided to drop toast again.

Let say side up is H and side down is T

If we want it to land side up three times in total, we must have it land H one time and other times T.

we have two possible outcomes; 
HT or TH out of four outcomes in total $\rightarrow \dfrac{2}{4} = \boxed{\dfrac{1}{2}}$

geerky42 · Answer

Is that clear?

anonymous · Answer

Yes, thx! Do you know how would I find the probability of this:

Jim picked a card from a standard deck, looked at it, and then put it back. He then picked a second card. What is the probability that Jim picked a heart or an ace on either pick? 
one over fifty two 

 two over fifty two 

 sixteen over fifty two 

 seventeen over fifty two 


*I don't see how 52 is in denominator..?

geerky42 · Answer

yeah, 52 is in denominator, and numerator is total number of heart and aces.
there is 4 aces, right? and there is 13 hearts.
Since one of ace is already heart, we don't want to count it twice, so numerator is either 4+12 or 3+13

geerky42 · Answer

52 is in denominator because there is 52 cards in total.

geerky42 · Answer

$ Probability = \dfrac{Number \space of\space  ways\space  it\space  can \space happen
}{Total \space number\space of \space outcomes}$

anonymous · Answer

Oh, I see, so it would be 16/52! Thx again. I know nothing of how many cards are in a deck. lol

geerky42 · Answer

oh i see, that fine lol.

just so you know, card of desk is make up of four suits (Club, Spade, Heart and Diamond)
and each suit has 13 cards; ace, 2 to 10, then J, Q, and K.

geerky42 · Answer

13*4 = 52