Let's show the equation:
3+8.5x=y
8.5 would be the slope because that's the rate and 3 would be the y intercept because that where he started.
And also with Jacinda, she is increasing 10, so her's would be 10x=y
3+8.5x=10x; Let's get x alone, so we need them on the same side, so subtract 8.5x from 10x and from its own side.
3=1.5x
3/1.5=x=2
They would be the same at 2 hours, so it would take Jacinda 2 hours. LEt's make sure.
3+8.5(2)= 17+3=20
10(2)=20
They're equal at 2 hours, so it would take 2 hours for Jacinda to catch up to Raj.