Who's good with measurements

I'm sure this is simple math but than again, I'm pretty simple.

What I have says to add 60ml per liter. How much would that be per 150ml?

Thanks

150ml is 15% of a liter

you want 15% of 60 ml or add 9ml to the 150ml

here's another way :

60ml/1000ml = x/150ml

multiply each side by 150 to isolate x

(150)60/1000ml = x(150)/150 (150 cancels out, because 150/150 = 1)

so 9000/1000 = x

X = 9ml

Thanks!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!