Answer:
1) 25+7(n-1)
When the above 'n'(hours) is substituted on the equation, it equals up to the right cost.
2) Given that n represents the no.of bikes, you just plug it in to the equation below.
250+39(n-1)
= 250+39(20-1)
= 250+39*19
= 250+741
= 991
-- The area of the long skinny piece on top is (6 x 33) = 198
-- The length of the dotted line between the top and bottom pieces is (33-21) = 12
-- The area of the bottom piece is (12 x 15) = 180
-- The area of the whole thing is (198 + 180) = 378
-- The perimeter of the whole thing is (33 + 6 + 21 + 15 + 12 + 15 + 6) = 108
You have a bag containing 8 + 20 = 28 marbles.
After you pull a black marble you have 28 - 1 = 27 remaining marbles.
There are 20 yellow marbles in the bag.
The probability of pulling a yellow marble is now