A) 7! x 7! | B) 7! x 6! |

C) 6! x 6! | D) 7! x 5! |

Explanation:

The students should sit in between two teachers. There are 7 gaps in between teachers when they sit in a roundtable. This can be done in $7{P}_{6}$ways. 7 teachers can sit in (7-1)! ways.

Required no.of ways is = $7{P}_{6}.6!=7!.6!$

A) 25 : 28 | B) 36 : 7 |

C) 8 :25 | D) 12 : 7 |

A) M | B) J |

C) B | D) O |

Explanation:

Thus after arranging the letters as per English alphabetical series; we get; Thus 4th letter from the left end will be K.

A) 2 | B) 3 |

C) 4 | D) 5 |

A) T | B) X |

C) N | D) R |

Explanation:

The first, the seventh, the ninth and the tenth letters of the word RECREATIONAL are R, T, O and N respectively. Meaningful word from these letters is only TORN. The third letter of the word is ‘R’.

A) 16! × 2 | B) 14! × 2 |

C) 18! × 2 | D) 14! |

A) 1/5225 | B) 1/5525 |

C) 5525 | D) 1/525 |

Explanation:

n(S) = 52C3 = 132600/6 = 22100

n(E) = 4C3 = 24/6 = 4