It's sin 6 .....so b is the answer !
138 because 92/4 equals 23 which is the miles per gallon, then you multiply that by 6<span />
Between the probability of union and intersection, it's not clear what you're supposed to compute. (I would guess it's the probability of union.) But we do know that

For parts (a) and (b), you're given everything you need to determine

.
For part (c), if

and

are mutually exclusive, then

, so

. If the given probability is

, then you can find

. But if this given probability is for the intersection, finding

is impossible.
For part (d), if

and

are independent, then

.
One of your friends gives you $10 for a charity walkathon -- this is your beginning amount.
Another friend gives you an amount per mile -- you will to calculate this value.
After 5 miles, you have raised $13.50 total --
-- Since one friend gave you $10.00, subtract this from the $13.50 to give you the amount by walking the 5 miles
-- $10.00 - $13.50 = $3.50
-- Since you walked 5 miles, divide $3.50 by 5 to give you $0.70 per mile earned.
So, an equation that represents the amount of money earned is: y = $0.70x+$10.00.
This is in slope-intercept form; the slope is $0.70 and represents the amount of money earned per mile and the intercept is $10.00 and represents the initial amount of money that you were given.
3c^3. This is probably it. I'm pretty positive.