The first thing you have to do is find how fast Andrew was going. To find out you have to Divide how long he drove by the hours. So you have to divide 234 by 3. You will get 78.
Andrew's average speed is 78 km/h. Brian drove 5 km/h faster then Andrew. So it would be
78+5 =83 km/h.
Now we have to find out how much time Brian took to get from Dawson to Mayo. So its 234 divided by 83. And it equals 2.819277108.
So the 2 means 2 hours. We will keep the 2 aside for now and worry about the 0.819.
0.819 x 60 = 49.14
60 - 49.14 = 10.86
And because it said round to the nearest minute...
And the answer is 11 minutes!
So Brian took 11 less minutes than Andrew.