Multiply all the terms by the same value to eliminate fraction denominators a/9=-4 9 . a/9=9(-4) The dot means multiplication Then simplify to simplify cancel the multiplied terms that are in the denominator a=9 . -4 Multiply the number 9 . -4 =36 And don’t forget to add the negative sign so the answer is a= -36
An event has probability 1 if you're certain that it will happen. You are sure to pick a marble that's either yellow, green, red, or blue. So, this probability is 1.
There are more yellow marbles than blue marbles, so it's actually more likely that you'll pick a yellow one, rather than the blue one.
The probability of picking a green marble is given by the number of green marbles divided by the total number of marbles. Compute this ratio and see what you get.
Similarly, the probability of picking a black marble is given by the number of black marbles divided by the total number of marbles. There are no black marbles, so...