1.50 + 0.50(x-1) <u><</u> 25
1.50 + 0.50x - 0.50 <u><</u> 25
1 + 0.50x <u><</u> 25
<u>-1 -1</u>
0.50x <u><</u> 24
<u> ÷0.50 ÷0.50</u>
x <u><</u> 48
1.50 + 0.50x <u><</u> 25 ; x <u><</u> 47 miles 3rd option in the choices.
To check:
1.50 + 0.50(47) <u><</u> 25
1.50 + 23.50 <u><</u> 25
25 <u><</u> 25
7/21 or 1/3rd, it's just a ratio of white to all, there's 7 white straws and 21 in all, then you can simplify it down to 1/3rd.
At 1/8 of a gallon you can mow 2 1/4 so for 1 gallon just multiply 2 1/4 by 8
16+2 is 18