Two quantities, x and y, are directly proportional. if x is tripled, what happens to y? (20 points) a) it is multiplied by 1/3 b) it is tripled c) it is multiplied by 9 d) it depends on the starting value of x

b) It is tripled

Step-by-step explanation:

If x is directly proportional to y, then

x = ky ... 1

Wherw y = x/k

where k is the constant of proportionality.

If x is tripled, the equation becomes

3x = kyo ... 2

From equation 2, yo = 3x/k

Where yo is the new value of y when x is tripled

Based in the new value of y, it can be seen that y also tripled as x tripled.

Note that in a direct variation, increase or decrease in a variable leads to equal increase or decrease in the other variable.

0.16 or 16%

step-by-step explanation:

lets take a coin for example.

if you toss it twice, it has a 1/4 chance of landing on heads both times because 1/2 * 1/2 is 1/4.

with the cards, the chance of picking dog is 0.4. having two people pick one is like picking a card twice in a row. so 0.4 * 0.4 is 0.16, or 16%