RRB NTPC CBT 2 Level 5 June-12-2022 Shift 1 Exam Previous Question Paper with Solutions

86) The LCM of two numbers is 20 times their HCF, and the sum of the LCM and the HCF is 504. If the difference of the numbers is 24, then find the sum of the numbers.

A) 210
B) 180
C) 225
D) 216

View Answer
D) 216

Explanation:We are given:
* LCM = 20 × HCF
* LCM + HCF = 504
* Difference of the numbers = 24
* We need to find the sum of the two numbers

Let HCF = x
Then LCM = 20x
So:
x + 20x = 504 ⇒ 21x = 504 ⇒ x = \frac{504}{21} = 24
Now:
* HCF = 24
* LCM = 20 × 24 = 480

Let the two numbers be 24a and 24b
(Since HCF is 24, both numbers are multiples of 24)
Also,
\text{LCM} = \frac{24a × 24b}{\text{HCF}} = \frac{24a × 24b}{24} = 24ab = 480 ⇒ ab = \frac{480}{24} = 20
And the difference of numbers is:
24a – 24b = 24 ⇒ a – b = 1
Now:
a – b = 1, ab = 20
Use these to solve for a and b:
From a - b = 1 ⇒ a = b + 1
Substitute into ab = 20:
(b+1)(b) = 20 ⇒ b^2 + b - 20 = 0 ⇒ (b+5)(b-4) = 0 ⇒ b = 4,\ a = 5
So the numbers are:
24a = 24×5 = 120, 24b = 24×4 = 96
⇒ Sum = 120 + 96 = 216

✅ Correct Answer: 4. 216

87) The present average age of X, Y and Z is 44 years. 8 years ago the average age of X and Y was 38 years. What is the present age of Z?

A) 39 years
B) 38 years
C) 41 years
D) 40 years

View Answer
D) 40 years

Explanation:We are given:
* Present average age of X, Y, Z = 44 years
⇒ Total = 44 × 3 = 132 years
* 8 years ago, average age of X and Y = 38 years
⇒ Total age of X and Y 8 years ago = 38 × 2 = 76
So, present total age of X and Y =
76 + 8×2 = 76 + 16 = 92
Now, present age of Z =
132 − 92 = \boxed{40} \text{ years}

88) Who became the first Indian female athlete to win two individual Olympic medals?

A) Mirabai Chanu
B) Dutee Chand
C) PV Sindhu
D) Ankita Raina

View Answer
C) PV Sindhu

89) In a certain code language, ‘RICE’ is coded as ‘5136’, ‘FUR’ is coded as ‘327’, and ‘FIN’ is coded as ‘785’. How will FUN’ probably be coded in that language?

A) 258
B) 182
C) 872
D) 718

View Answer
C) 872

90) In each of the given number-clusters, the number on the right side of (the equal to sign)is calculated by performing certain mathematical operations on the three numbers on the left of = (the equal to sign). All three number-clusters follow the same pattern. Select the number from among the given options that can replace the question mark (?) in the third number-cluster.
21, 9, 40 =149
18, 7, 25 =101
15, 11, 30=?

A) 110
B) 120
C) 125
D) 135

View Answer
D) 135

Explanation:We are given three number clusters:
⇒1. 21, 9, 40 = 149
⇒2. 18, 7, 25 = 101
⇒3. 15, 11, 30 = ?
Let’s find the logic behind the pattern.

Step-by-step pattern check:
First cluster:
21, 9, 40 = 149
Try:21 × 9 = 189,
Then 189 – 40 = 149 ✅
Second cluster:
18, 7, 25 = 101
Try:18 × 7 = 126,
Then 126 – 25 = 101 ✅
So the pattern is:
> (First × Second) – Third = Result

Apply to third cluster:
15, 11, 30 = ?
15 × 11 = 165
165 – 30 = 135

✅ Final Answer: 135

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