The interest rate in the economy is 3%. Two ZCB (A and B) are trading, their Face value (FV) $100; you can go long or short on any of them.

Bond A matures in 5 Years and has Face value (FV) $100,

bond B- matures in 10Y and has Face value (FV) $100,

You own 100 A bonds and cannot sell them for next year. You hear a rumor that FED will change rates overnight to 5%.

How many B bonds do you need to sell short to hedge your position ?