RRB PO Prelims | Memory Based Paper 20 August 2022 Shift 1 Quantitative Aptitude

Question 1.

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What approximate value should come in place of the question mark (?) in the following question?

√168.99 × 10.01 - 2.99 × ? = (7.04)²

21

24

27

30

33

Detailed Solution

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Answer 

Option 3 : 27

Given:

√168.99 × 10.01 - 2.99 × ? = (7.04)2

Rules of Approximation:

1. If a number has digits to the right of the decimal less than 5, then just drop the digits to the right of the decimal. The number so obtained will be the approximated value.

2. If a number has digits to the right of the decimal more than 5, then just drop the digits to the right of the decimal and raise the remaining number by '1'.The number so obtained will be the approximated value.

Concept used:

Follow the BODMAS rule according to the table given below:

Calculation:

√168.99 × 10.01 - 2.99 × ? = (7.04)2

⇒ √169 × 10 - 3 × ? = 7²

⇒ 13 × 10 - 49 = 3 × ?

⇒ 3 × ? = 130 - 49

⇒ 3 × ? = 81

⇒ ? = 27

∴ 27 should come in place of the question mark (?).

Question 2.

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What should come in place of question mark in the following question ?

864.02 ÷ 3.99 + 38.05 ÷ 18.98 × 110.01 = ?

330

452

395

436

334

Answer (Detailed Solution Below)

Option 4 : 436

Detailed Solution

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Calculation:

864.02 ÷ 3.99 + 38.05 ÷ 18.98 × 110.01 = ?

⇒ 864 ÷ 4 + 38 ÷ 19 × 110 = ?

⇒ 216 + 2 × 110 = ?

⇒ 216 + 220 = ?

⇒ 436 = ?

∴ The value of ? is 436

Question 3.

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What approximate value should come in the place of question mark (?) in the following question?

936.43 ÷ 13 ÷ 3.99 × 12 – 13.48 × 13.33 = ?

47

64

50

23

32

Answer (Detailed Solution Below)

Option 1 : 47

Detailed Solution

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Given:

936.43 ÷ 13 ÷ 3.99 × 12 – 13.48 × 13.33 = ?

Concept Used:

Calculation:

936.43 ÷ 13 ÷ 3.99 × 12 – 13.48 × 13.33 = ?

⇒ 936 ÷ 13 ÷ 4 × 12 – 13 × 13 = ?

⇒ 936 ÷ 13 ÷ 4 × 12 – 13 × 13 = ?

⇒ ? = 72 ÷ 4 × 12 – 169

⇒ ? = 18 × 12 – 169

⇒ ? = 47

∴ The value of (?) is 47.

Question 4.

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What should come in place of question mark in the following question ?

(63.99)^1/3 × 124.989 + 407.05 ÷ 10.98 = ?

537

425

754

224

256

Answer (Detailed Solution Below)

Option 1 : 537

Detailed Solution

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Calculation:

(63.99)1/3 × 124.989 + 407.05 ÷ 10.98 = ?

⇒ 4 × 125 + 407 ÷ 11 = ?

⇒ 4 × 125 + 37 = ?

⇒ 500 + 37 = ?

⇒ 537 = ?

∴ The value of ? is 537

Question 5.

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What should approximate will come in the place of the question mark ‘?’ in the following question?

(23.42 + 17.43) ÷ 2 × 4 – 48.25 + 643.86 = ?

521

634

598

676

741

Answer (Detailed Solution Below)

Option 4 : 676

Detailed Solution

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Calculation:

(23.42 + 17.43) ÷ 2 × 4 - 48.25 + 643.86 = ?

⇒ (23 + 17) ÷ 2 × 4 – 48 + 644 = ?

⇒ (23 + 17) × 2 + 596 = ?

⇒ 40 × 2 + 596 = ?

⇒ ? = 676

∴ The value of (?) is 676.