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Elementary Mathematics Flashcards

6 cards from real CDS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 6 Elementary Mathematics flashcards as text

  1. If the simple interest on $500 at 6% per annum for 3 years is calculated, what is the interest amount?

    Answer: $90

    Simple Interest = (P × R × T) / 100 = (500 × 6 × 3) / 100 = $90.

  2. What is the sum of interior angles of a hexagon?

    Answer: 720°

    Sum of interior angles = (n − 2) × 180° = (6 − 2) × 180° = 720°.

  3. If 2x + 5 = 17, what is the value of x?

    Answer: 6

    2x = 17 − 5 = 12, so x = 6.

  4. The average of five numbers is 24. If four of them are 18, 22, 28, and 30, what is the fifth number?

    Answer: 22

    Total sum = 24 × 5 = 120; fifth number = 120 − (18+22+28+30) = 120 − 98 = 22.

  5. A circle has a radius of 7 cm. What is its circumference? (Use π = 22/7)

    Answer: 44 cm

    Circumference = 2πr = 2 × (22/7) × 7 = 44 cm.

  6. What is the square root of 1764?

    Answer: 42

    42 × 42 = 1764, so √1764 = 42.

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Sources & references

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  1. upsc.gov.in — Test delivery, fees, exam format, passing score, retake policy, time limit · verified Oct 2026