If 3 sisters and 8 brothers are together playing a game, then the number of ways in which all the sisters and brothers are to be seated around a circle such that all the three sisters are not seated together is

Out of 8 students in a classroom, 4 of them are chosen and they are arranged around a table.

If the remaining 4 are arranged in a row, then the total number of arrangements that can be made with those 8 students is

Three letters are chosen at random from the letters of the word VARIABLE and all possible three letter words (with or without meaning) are formed with them.

Then, the probability of getting a three letter word having a consonent as its middle letter is

If ${ }^{27} P_{r+7}=7722{ }^{25} P_{(r+4)}$, then $r=$