The key is Esther travelled the same distance - x - in both her morning and evening commute.
45(time she took in the morning, or p) = x
30(time she took in the evening, or q) = x
Therefore 45(p) = 30(q), or divide both sides by 5 and get 9(p) = 6(q). I know you can divide it further, but these numbers are small enough and it's not worth the time.
Since the whole trip took an hour, (p + q) = 60min, and so, p = 60-q.
Therefore 9(60-q) = 6q or 540-9q = 6q. So 540 = 15q, which makes q = 36. If q = 36, then by (p+q)=60, p (the time she took in the morning) must equal 24.
45 miles per hour, her speed in the morning, times (24/60) hours, her time, makes 18 miles travelled in the morning. If you check, 30 miles per hour times (36/60) hours also makes 18 miles in the evening.
<span>Hope that makes a little sense. And I also hope it's right</span>
The first statement is true.
The second statement is false.
The third statement is true.
The easiest way to find the factors of a pair of numbers, is simply to
write out the factors until you find the ones that they have in common.
So in this case, these factors would be listed as follows:
20: 1,2,4,5,10,20
50: 1,2,5,10,25,50.
From looking at these numbers, we can therefore see that the common factors are: 1,2,5,10