The swimmer swam at in increasing speed as time passed, then came to a constant speed. When the line is horizontal, that means he is continuously moving, but his speed is not increasing. Then the swimmer starts to slow down in speed and time towards the end.
y=3/2x+3 that is the answer
85/15 is 5 2/3
so, to find 85% with 15%, you would multiply 12 (also 15%) by 5 2/3.
12*5 2/3=68.
you could also find it using the 1% method:
1% of 15 is .15.
.15*85=68.
Hope this helps!