Pls help me I am so confused on this problem

hello 0xxbadwolfxx0,

2.6 x 10^9 is 2,600,000,000.

1.3 x 10^2 is 130

multiplying 130 and 2,600,000,000 would simply give you 200,000,000,000.

therefore, the answer would be d. 2.0 × 10^11.

i hope i ! warm regards, mae.

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.