The Beatles have a concert that starts in 17 minutes and they must all cross a bridge to get there. All four men begin on the same side of the bridge. It is nightfall, and there is only one flashlight. A maximum of two people can cross at one time. Any party who crosses, either 1 or 2 people, must have the flashlight with them, and the flashlight must be walked back and forth. Each band member walks at a different speed. A pair must walk together at the rate of the slower man's pace:

*Ringo: - 1 minute crossing
*George: - 2 minutes crossing
*Paul:- 5 minutes crossing
*John: - 10 minutes crossing

Example: If Ringo and John go first, 10 minutes have elapsed when they get to the other side of the bridge. If John then returns with the flashlight, a total of 20 minutes have passed and they have missed the concert.

There are two known answers to this problem.

The amino acids in the amino acid sequences of the polypeptide chains of human proteins differ from those of chimpanzees by approximately what percentage?

(1) 1%
(2) 8%
(3) 20%
(4) 30%
(5) 45%

The heat of combustion for 1m of carbon to carbon dioxide is -410 kJ. How many kJ of heat would escape from the combustion of 60.0 g of carbon?

(1) -65 kJ
(2) -1680 kJ
(3) -2050 kJ
(4) -135 kJ