8 7 10 10 9 6 what is the probability of drawing one of the 7 and one of the 10

Question

jane choses one but does not put the number back with it

Answer 1

There are six cards, one of them with a 7, so we have a one in six chance, or 1/6.

After a card is pulled out, there are five cards left. Two of those are 10, so that would be a 2/5 chance.

 

Next we multiply these fractions together:

 

¹/₆ * ²/₅ = ²/₃₀ → ¹/₁₅

 

What if we looked at the ten cards first? that would be 2/6, then once that's pulled, 1/5 for the seven card:

²/₆ * ¹/₅ = ²/₃₀ → ¹/₁₅

 

So there is a 1/15 probability that a seven and a ten will be pulled. You can divide the fraction if you're looking to make it a percentage.