Question

a box contain 10 pins 3 are blue and 7 are green two pins are randomly taken out of the box without replacement work out the probability that both pins are the same colour

Answer 1

Answer:

7/120

Step-by-step explanation:

P=(3/10)(7/9)(2/8)

P=7/120

since we were ask to find the probability of chosing 1 red, 1 black and 1red marble without replacement after each draw we can use the fundamental method in finding the probability.

There are 3 red marbles and 7 black marbles.

In the first case, we need to have a red marble so we need to find how many red marble are there and divide it by the total number of marbles.

In the second case, it is black, so since the number of black marbles is already given, we only need to divide it by the total number of marble minus the number of marbles removed.

Same goes for the last marble, but since we reduced a red marble from the first case so the number of remaining red marbles divided by the remaining marbles.