I Need Some Mathematical Guidance On Charge-Time.

[TwiceDead]

Educate me on this because I can't figure this out. 

I looked at Lanka's charge speed on the wiki. It says 1.5 seconds to charge.

When you equip both Speed Trigger and Shred, both maxed out, you increase your fire-rate by 90%, or in this case decrease the charge-time by 90%. 

 

I know the answer lies around 0.75, but I want to know the exact number and how to reach that conclusion. 

What I tried to do, but failed, was the following and they are both so obviously wrong I am ashamed of myself:

1.5 x 0.1 = 0.15 x 9 = 1.35

1.5 x 0.9 = 1.35

 

... Lol how I failed. 

So how do you actually do this math? 

 

EDIT:

Second attempt:

 

1.5 / 2 = 0.75
0.75 x 0.1 = 0.075

0.075 x 11 = 0.825

 

Seems about right...right? 

 

EDITx2:
NOPE! It was wrong. Anyhow issue resolved thanks to the below, so feel free to let this thread DIE. 

Edited September 12, 2013 by TwiceDead

[dongstrong]

1.5/1.9=0.789~

[TwiceDead]

Thank you. :)