25,000 bricks were used to build the new library. the total weight of the bricks was 30,000 pounds. what is the weight of each brick? which let statement(s) would you use?

correct answer was 0.5

in counting the number of heads in 4 coin flips, the probability that we get exactly one head is the probability that we get anyone of the following 4 outcomes: httt, thtt, ttht, or ttth. each has probability 1/16, so the probability to get exactly one head in 4 flips is 1/16 + 1/16 + 1/16 + 1/16 = 4/16 = 1/4.