A) 28 | B) 29 |

C) 31 | D) 35 |

Explanation:

Clearly, we have :

A = B - 3 ...(i)

D + 5 = E ...(ii)

A+C = 2E ...(iii)

B + D = A+C = 2E ...(iv)

A+B + C + D + E=150 ...(v)

From (iii), (iv) and (v), we get: 5E = 150 or E = 30.

Putting E = 30 in (ii), we get: D = 25.

Putting E = 30 and D = 25 in (iv), we get: B = 35.

Putting B = 35 in (i), we get: A = 32.

Putting A = 32 and E = 30 in (iii), we get: C = 28.

A) 6 | B) 9 |

C) 7 | D) 5 |

Explanation:

Arithmatic mean = sum/members

=> (1x1 + 2x2 + 3x3 + 4x4 + 5x5 + 6x6 + 7x7) / (1 + 2 + 3 + 4 + 5 + 6 + 7)

=> 140/28 = 5

A) 5 | B) 4 |

C) 7 | D) 6 |

Explanation:

Let the number be x. Then,

- 4x = x + 50

- 5x - 50 = 0

(3x + 10)(x - 5) = 0

x = 5

A) 30 | B) 27 |

C) 23 | D) 33 |

Explanation:

Then, A:B = 2:3 and B:C = 5:8

= (5 x 3/5) : (8 x 3/5) = 3:24/5

A:B:C = 2:3:24/5

= 10:15:24 => B = 98 x 15/49 = 30.

A) 4 | B) 10 |

C) 8 | D) 5 |

Explanation:

If Vijay gives 'x' marbles to Ajay then Vijay and Ajay would have V - x and A + x marbles.

V - x = A + x --- (1)

If Ajay gives 2x marbles to Vijay then Ajay and Vijay would have A - 2x and V + 2x marbles.

V + 2x - (A - 2x) = 30 => V - A + 4x = 30 --- (2)

From (1) we have V - A = 2x

Substituting V - A = 2x in (2)

6x = 30 => x = 5.

A) 10 | B) 6 |

C) 35/4 | D) 45/4 |

Explanation:

As clear from the figure itself, triangle OQX and triangle O'PX are similar.

So,

OQ/O'P = OX/O'X

=> OX = (7/9)xO'X

And since, OX + O'X = 20

=> (7/9)xO'X + O'X = 20

=> O'X = 45/4