White - 20 marbles
black - 30 marbles
beige - 40
there are are also purple marbles in the bag. which of the following can not be the probability of randomly selecting a purple marble from the bag ?
a. 1/10
b. 1/5
c. 2/5
d. 7/15

( give an explanation)

d

Step-by-step explanation:

The probability of not being purple is the probability of the three other colors. Suppose the number of purple marbles is x. Then we have 20+30+40+x = 90 + x marbles. Then the probability of not being purple is 90/(90+x). If this fraction can have a lowest term for some value of x, then the numerator of this lowest term must be a factor of 90.

Checking through the options, only option D has a non-factor of 90 as its numerator.

hello from mrbilldoesmath!

answer:

x - 3

discussion:

x^2 - 9 = (x-3) (x+3)   so

(x^2-9)/ (x + 3) = x-3

you,

mrb

a function could be identified in 3 ways either on a chart,graph, or ordered pairs. first a function is that each point has its own. the rule is that there can be many x's to one y but there can not be 2 x's at different y's. so on a graph when you put a straight line through the y's there should be one dot only to be a function.

step-by-step explanation: