Important for :

1

D

Let x be the number of students in the class and y be the average weight of the class

Now according to question,
xy + 50 | = y + 1 |

x + 1 |

xy + 50 + 50 | = y + 1.5 |

x + 2 |

1.5x + 2y = 97 .......... (ii) From equation (i) and (ii), we get y = 47

Hence, option (D) is correct.

2

D

Sales tax on the article sold at Rs. 400 = | 400 × 7 | = 28 |

100 |

Sales tax on the article sold at Rs. 6400

= | 6400 × 9 | = 576 |

100 |

Total tax = 28 + 576 = 604

Percentage sales tax = | 604 | × 100 = | 151 | = 8 | 15 | % |

6800 | 17 | 17 |

Hence, option (D) is correct.

3

B

Average salary of male employees = Rs. 6000Average salary of female employees = Rs. 5600

Mean salary = Rs. 5800

By using alligation

(6000) | (5600) | |||

\ | / | |||

(5800) | ||||

/ | \ | |||

200 | 200 |

∴ The ratio of male : female = 200 : 200 = 1 : 1

Hence, % of female employees = | 1 | × 100 = 50% |

2 |

Therefore, option (B) is correct.

4

C

Total salary of 65 workers = 65 × 5680 = Rs. 369200

Total salary of 31 workers = 31 × 2356 = Rs. 73036

Total salary of 23 workers = 23 × 4589 = Rs. 105547

No. of remaining workers = 65 – 31 – 23 = 65 – 54 = 11

Total Salary of 11 workers = 369200 – 73036 – 105547 = 369200 – 178583 = Rs. 190617

Required average = | 190617 | = 17329(approx) |

11 |

Hence, option C is correct.

5

A

The average rate of percentage increase in both the cases- weekly and yearly will be the same.

Therefore, annual percentage in sales = | 21 – 15 | × 100 |

15 |

= | 600 | = 40% |

15 |

Hence, option A is correct.