Zoho Field Formula

Zoho Field Formula

Hi I am using the following formula to multiply some fields by an hourly rate and total them together. This part of the formula works fine. I now want to take the total calculated by the formula and ad 20% to the total.  I cant seem to get this bit of the code correct 


${Quotes.Upfront Payment}+${Quotes.Type 1 Hours}*(160)+${Quotes.Type 2 Hours}*(185)+${Quotes.Type 3 Hours}*(230)


Can anyone offer some help