A) 235 | B) 253 |

C) 325 | D) None of these |

Explanation:

Required number of signals =

= 5 + 20 + 60 + 120 + 120 = 325

A) 1,00,000 | B) 59,049 |

C) 3439 | D) 6561 |

Explanation:

The numbers 0,1,2,3,4,5,6,7,8,9 are 10 in number while preparing telephone numbers any number can be used any number of times.

This can be done in ways, but '0' is there

So, the numbers starting with '0' are to be excluded which one in number.

Total 5 digit telephone numbers = = 3439

A) 240 | B) 72 |

C) 48 | D) 36 |

Explanation:

DESIGN = 6 letters

No consonants appears at either of the two ends.

=

= 2 x 4 x 3 x 2 x 1

= 48

A) 360 | B) 720 |

C) 120 | D) 840 |

Explanation:

CAPITAL = 7

Vowels = 3 (A, I, A)

Consonants = (C, P, T, L)

5 letters which can be arranged in

Vowels A,I =

No.of arrangements = =360

A) 2520 | B) 2880 |

C) 4320 | D) 5040 |

Explanation:

The number of ways of arranging n beads in a necklace is (since n = 8)

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 betweeen teachers when they sit in a round table. This can be done in ways. 7 teachers can sit in (7-1)! ways.

Required no.of ways in =