Divide miles, speed time formatting

[jackwebso]

Hi, I am trying to display in minutes, instead of 0.2 hr etc
like the example below will do, now I know every .1 = 6 min
I am just stumped on how to get this to display 12 minutes.

PHP Code:
$sum = round(11 / 55,1);// example 11 miles
echo $sum;
I am trying to display things in minutes only when under 1 hour
Anyone know how to multiply just that number after the decimal by 6?