Annual pay to spot rates

CFA Level II Fixed Income
#1

TOs goes back to level 1 how do you get spot rates from annual pay bonds. The question gives me "one year annual pay bond is 2% for a benchmark two year annual pay bond is 3% and for a benchmark three-year annual-pay bond is 4%z they derived spot rates of 2%, 3.015% and 4.055% respectively and I can’t figure out how to calculate it.

Thank you

#2

Bootstrapping.

I wrote an article on yield curves that covers this: http://financialexamhelp123.com/par-curve-spot-curve-and-forward-curve/