RRB NTPC Graduation 2025  Discount (maths) Related Questions and answers

19/06/2025 Shift-2

18%, 24% ಮತ್ತು 18% ಎಂಬ ಮೂರು ಕ್ರಮಬದ್ಧ ರಿಯಾಯಿತಿಗಳ ನಂತರ, ಗುರುತಿಸಿದ ಬೆಲೆಯ ಪರಿಣಾಮಕಾರಿ ಶೇಕಡಾವಾರು ಬೆಲೆಯನ್ನು (ದಶಮಾಂಶದ ನಂತರ ಎರಡು ಸ್ಥಾನಗಳಿಗೆ ರೌಂಡ್ ಮಾಡಿ) ಕಂಡುಹಿಡಿಯಿರಿ.

English Question:

Find the effective price percentage of the marked price after three consecutive discounts of 18%, 24% and 18%.
(Rounded up to two decimal places.)

Options:

A) 51.10%
B) 54.41%
C) 48.56%
D) 53.54%

Correct Answer: A

We can solve this step by step.

---

🟢 Step 1: Use the formula for effective price after successive discounts

If successive discounts are (d_1, d_2, d_3), the effective price percentage (EPP) is:

[
\text{EPP} = (1 - d_1)(1 - d_2)(1 - d_3) \times 100
]

Where discounts are in decimal form.

---

🟢 Step 2: Convert percentages to decimals

• d₁ = 18% = 0.18

• d₂ = 24% = 0.24

• d₃ = 18% = 0.18

---

🟢 Step 3: Multiply complements

[
(1 - d_1)(1 - d_2)(1 - d_3) = (1 - 0.18)(1 - 0.24)(1 - 0.18)
]

[
= 0.82 × 0.76 × 0.82
]

---

Step 3a: Multiply first two

0.82 × 0.76 = 0.6232

Then multiply by 0.82:

0.6232 × 0.82 ≈ 0.5110

---

🟢 Step 4: Convert to percentage

[
\text{Effective Price %} = 0.5110 × 100 ≈ 51.10%
]

---

🎯 Final Answer:

51.10% of the marked price

17/06/2025 Shift-3

2)26%, 29% ಮತ್ತು 2% ಎಂಬ ಮೂರು ಕ್ರಮಬದ್ಧ ರಿಯಾಯಿತಿಗಳಿಗೆ ಸಮಾನವಾದ ಏಕೈಕ ರಿಯಾಯಿತಿಯನ್ನು (ದಶಮಾಂಶದ ನಂತರ ಎರಡು ಸ್ಥಾನಗಳಿಗೆ ರೌಂಡ್ ಮಾಡಿ) ಕಂಡುಹಿಡಿಯಿರಿ.

English Question:

Find a single discount (rounded up to two decimal places) equal to three consecutive discounts of 26%, 29% and 2%.

Options:

A) 47.56%
B) 47.12%
C) 48.51%
D) 48.86%

Correct Answer: C

We can solve this step by step.

---

🟢 Step 1: Use the formula for successive discounts

If three successive discounts are d₁, d₂, d₃, the equivalent single discount (D) is given by:

[
D = 1 - (1 - d_1)(1 - d_2)(1 - d_3)
]

Where discounts are in decimal form.

---

🟢 Step 2: Convert percentages to decimals

• d₁ = 26% = 0.26

• d₂ = 29% = 0.29

• d₃ = 2% = 0.02

---

🟢 Step 3: Multiply complements

[
(1 - d_1)(1 - d_2)(1 - d_3) = (1 - 0.26)(1 - 0.29)(1 - 0.02)
]

[
= 0.74 × 0.71 × 0.98
]

---

Step 3a: Multiply first two

0.74 × 0.71 = 0.5254

Then multiply by 0.98:

0.5254 × 0.98 ≈ 0.515892

---

🟢 Step 4: Find single discount

[
D = 1 - 0.515892 \approx 0.484108
]

Convert to percentage:

[
D ≈ 48.41%
]

---

🎯 Final Answer:

48.41%

3)