Important for :

1

C

Let the amount invested in Scheme A is ₹ x.Then, the amount invested in Scheme B be ₹ (6100 – x)

Now, according to the question,

x | ( | 1 + | 10 | ) |
^{2} |
– x = | (6100 – x) × 10 × 4 |

100 | 100 |

⇒ x | ( | 121 | – 1 | ) | = | (6100 – x) × 40 |

100 | 100 |

⇒ | 21x | = | (6100 – x) × 40 |

100 | 100 |

⇒ 21x = 6100 × 40 – 40x

⇒ 61x = 6100 × 40

⇒ x = | 6100 × 40 | = ₹ 4000 |

61 |

∴ The amount invested in Scheme A is ₹ 4000.

Hence, option C is correct.

2

3

B

Let the amount invested in Scheme A is ₹ x.

Then, the amount invested in Scheme B therefore will be ₹ (40000 – x)

We know that for the 1st year both Simple Interest and Compound Interest on a sum remains the same. Now, according to the question,

⇒ 15% of x = 10% of (40000 – x)

⇒ 15x = 400000 – 10x

⇒ 25x = 400000

⇒ x = 16000

Hence, option B is correct.

4

B

P = ₹ 110000; R = 11%; n = 2 years

CI = P | ( | 1 + | R | ) |
^{n} |
– P |

100 |

CI = 110000 | ( | 1 + | 11 | ) |
^{2} |
– 110000 |

100 |

= 110000 | ( | 111 | ) |
^{2} |
– 110000 |

100 |

= 135531 – 110000 = ₹ 25531

_________________________________________

To solve this question, we can apply the net% effect formula

Net% effect = | ( | x + y + | xy | ) | % |

100 |

Here, x = y = 11% (because rate of interest is same for both the years)

By the net% effect, we get effective rate of interest

= | ( | 11 + 11 + | 11 × 11 | ) | % = 23.21% | |

100 |

Therefore, 23.21% of 110000 = ₹ 25531

Hence, option B is correct.

5

D

P = ₹ 12000; R = 3%; n = 2 years

CI = | P | ( | 1 + | R | ) |
^{n} |
– P |

100 |

CI = | 12000 | ( | 1 + | 3 | ) |
^{2} |
– 12000 |

100 |

= 12000 × | 103 | × | 103 | – 12000 |

100 | 100 |

= 12730.8 – 12000 = ₹ 730.8

_____________________________________________

To solve this question, we can apply the net% effect formula

Net% effect = | ( | x + y + | xy | ) | % |

100 |

Here, x = y = 3% (because rate of interest is same for both the years)

By the net% effect, we get effective rate of interest

= | ( | 3 + 3 + | 3 × 3 | ) | % = 6.09% | |

100 |

Therefore, 6.09% of 110000 = ₹ 730.8

Hence, option D is correct.