The water level in an ocean changes at an average rate of 3 meters per hour. At this rate, how many hours would it take for the water level to change 12 meters?

4 hours

Step-by-step explanation:

The water level changes at an average rate of 3 meters per hour.

The question wants to know how long it will take for the ocean water level to change 12 meters.

You can use direct proportion:

1 hour     :  3 meters

x hours   : 12 meters

Cross multiply to get:

3x = 12

x = 12 / 3

= 4 hours

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%