In a bag of keys, there are 13 silver keys, 6 black keys, 11 copper keys, and 2 painted keys of various colors. One key is drawn out at random. What is the probability that the key that is drawn is silver or copper?

The best thing to do here is to put each of these into fractions, with the total (31) as the denominator.

14/31= silver

6/31= black

8/31= copper

3/31= various colours.

As you're looking for the keys that are silver or copper, you've got to add the two denominators together, which gives you 14+8= 22.

This cannot be simplified further, therefore, the probability of choosing either a silver or copper key is 22/31

Hope this helps :)

just keep asking questions until you have a better understanding.

step-by-step explanation:

1,407.5 hours

step-by-step explanation:

we first convert all the time to hours and then sum them up.

there are 24 hours in 1 day, in 58 days, there are 24 x 58 = 1,392 hours.

there are 60 minutes in 1 hour, thus, 30 minutes will be equivalent to 30 / 60 = 0.5 hours.

therefore, the number of hours it will take mercury to complete a full rotation is 1,392 + 15 + 0.5 = 1,407.5 hours