Bond - interest rate - maturity question...need help

[BuckStocksHere]

so I'm stuck on this -

___hypothetical situation_____

I have 2 bonds
10,000 US Treasury Bonds ------------Term 10 ----------- Duration 7.12yrs ----- Current FMV = $10,0000

5,000 US Treasury Bonds -------------Term 20 ------------Duration 9.95yrs ---------Current FMV = $5,000

If Interest Rates for all maturities increase by 1.0%, what will be the approximate value of the bonds in the portfolio?


I feel like I should know how to do this and I am COMPLETELY brain dead stuck..... any help out there?!?! please!

 

[Bucklion]

I just use the online bond calculator...because I can't do them either

http://www.treasurydirect.gov/indiv/tools/tools_savingsbondcalc.htm