# TCS Placement: Sample Questions 26 - 27 of 502

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## Question 26

### Question

MCQ▾How would the decimal number 520 be represented in a base 7 number System?

### Choices

Choice (4) | |
---|---|

a. | 1672 |

b. | 1562 |

c. | 1234 |

d. | 1342 |

### Answer

d.### Explanation

- Dividing number 520 (base 10) by 7, quotient is 74 and remainder is 2
- Dividing number 74 by 7, quotient is 10 and remainder is 4
- Dividing number 10 by 7, quotient is 1 and remainder is 3
- Dividing number 1 by 7, quotient is 0 and remainder is 1
- Reversing the order of remainders equivalent of 520 (base 10) will be 1342 (base 7)
- So, equivalent number is 1342 in base 7 for decimal number 520.

## Question 27

### Explanation

- Here, difference between first and second term is 1, i.e.. 9 + 1 = 10
- Difference between second and third term is 1, i.e.. 10 + 1 = 11
- Difference between third and fourth term is 2, i.e.. 11 + 2 = 13
- Difference between fourth and fifth term is 2, i.e.. 13 + 2 = 15
- Difference between fifth and sixth term is 3, i.e.. 15 + 3 = 18
- Difference between sixth and seventh term is 3, i.e.. 18 + 3 = 21
- Difference between seventh and eighth term is 4, i.e.. 21 + 4 = 25
- Applying this pattern we are getting the exact series terms.
- So, series is 9, 10, 11, 13, 15, 18,21, 25
- Missing term is 18.