" An open end series is that series in which: "

Let v_(1) be the frequency of series limit of Lyman series, v_(2) the frequency of the first line of Lyman series and v_(3) the frequency of series limit of Balmer series. Then which of the following is correct ?

Let v_(1) be the frequency of series limit of Lyman series, v_(2) the frequency of the first line of Lyman series and v_(3) the frequency of series limit of Balmer series. Then which of the following is correct ?

The end product of 4n series is

The end product of 4n series is