Mosfet Turn on/off time

[agganitk]

Hello
I am trying to calculate mosfet turn on & off times. I followed attached vishay app note. At the end of app note, an example is given for calculation. I did calculation  and  all result are matching  except high lighted one. I cross checked manytime my calculation but couldn't find any mistake. please let know where i am wrong.

For example, I should get 197 ns in result but getting 472 ns.