Yield Beta on Bond Futures

I’m confused as to when to factor in Yield Beta in addition to MD when calculating # of contracts to use on a hedge. Seems like it’s a distracter and not used in some questions but not so in others? What am I missing here? Having a problem with question 50 in the schweser practice exam volume 2 test 1 (afternoon).

Yield beta when given should be included

#F = (Yb)*[(BPVt-BPVp/BPVf)]*[Duration Gap/(PriceF*Multiplier)].

When yield beta isn’t given it is assumed to be 1.

Now I’m even more confused because I could have sworn i’d been ignoring it and still getting questions right. What exactly is yield beta conceptually? You would think MD of a contract and yield beta would essentially be the same thing no?

If it’s not included it’s 1 - not really ignored.

https://definedterm.com/yield_beta

right i’m talking about when it’s included and not 1 obviously