A) 1 | B) 2 |

C) 3 | D) 5 |

Explanation:

Use unitary method:

In hours, 123 typists can type 984 paper

In 1 minute, 123 typists can type = 246 papers

In 1 minute, 1 typist can type =2 papers [ Hint hours = 4 minutes]

A) 56 | B) 64 |

C) 87 | D) 78 |

Explanation:

Using Trial and error method,

we get the number of girls in the hall = 78

A) 33 yrs | B) 27 yrs |

C) 21 yrs | D) 29 yrs |

Explanation:

Let the avg age of 7 boys be 'p' years

Let the age of the girl be 'q' years

From given data,

The age of 7 boys = 7p years

Now the new average = (p + 1) when 22 yrs is replaced by q

Now the age of all 7 will become = 7(p + 1) yrs

Hence, 7p - 22 + q = 7(p + 1) yrs

7p - 22 + q = 7p + 7

q = 22 + 7 = 29

Therefore, the age of girl = q = 29 years.

A) 15 kg | B) 25 kg |

C) 35 kg | D) 45 kg |

Explanation:

Let the ratio of initial quantity of oils be 'x' => 4x, 5x & 8x.

Let k be the quantity of third variety of oil in the final mixture.

Let the ratio of initial quantity of oils be 'y'

From given details,

4x + 5 = 5y ..... (1)

5x + 10 = 7y .....(2)

8x + k = 9y ......(3)

By solving (1) & (2), we get

x = 5 & y = 5

From (3) => k = 5

Therefore, quantity of third variety of oil was 9y = 9(5) = 45kg.

A) 384 | B) 96 |

C) 192 | D) 206 |

Explanation:

Let the third subject marks be 'x'

=> Second subject marks = 2x

=> Third subject marks = 4x

Given avg = 224

x + 2x + 4x = 224 x 3

=> 7x = 224 x 3

=> x = 96

Hence, Second subject marks = 2x = 2 x 96 = 192.

A) 1000 (r - p) + pq | B) 1000 p + qr |

C) 1000 (r - q) + pr | D) 1000(p - q) + qr |

Explanation:

We need to find the total cost to send r messsages, r > 1000.

The first 1000 messsages will cost Rs.p each (Or)

The total cost of first 1000 messsages = Rs.1000p

The remaining (r - 1000) messsages will cost Rs.q each (Or)

The cost of the (r - 1000) = Rs.(r - 1000)y

Therefore, total cost = 1000p + rq - 1000q

= 1000(p - q) + qr