The maximum wavelength of Brackett series of hydrogen atom will be _____`A^(@)`

Explanation

`n_(1)=4 and n_(2)=5 therefore (1)/(lambda_("max"))=R[(1)/(4^(2))-(1)/(5^(2))] `
or ` lambda_("max") = (25 xx16xx10^(10))/(9xx1.1xx10^(7))=40400`Å