Guinness World Records (General Knowledge Focus) MCQs with Answers & Explanations (Page 491)

Explanation Original price = Rs. 2,000 Increase = 15% of 2,000 15/100 ​ × 2000 = 300 New price: =2000 + 300 = 2300

Explanation Let the number of 20-cent coins = x Then 50-cent coins = 54 − x 0.20x + 0.50(54 − x) = 20.70 x = 23 Last updated 27-07-2026 by NA

Explanation Given: 2 × 1^ 2 + 4 × 2^ 2 + 6 × 3^ 2 + ⋯ + 20 × 1 0^2 Write the terms as: 2 ( 1^ 3 ) + 2 ( 2^ 3 ) + 2 ( 3^ 3 ) + ⋯ + 2 ( 1 0^ 3 ) = 2 ( 1^ 3 + 2^ 3 + 3^ 3 + ⋯ + 1 0^ 3 ) Using the formula: 1^3+2^3+cdots+n^3=left[frac{n(n+1)}{2}right]^2 1^ 3 + 2^ 3 + ⋯ + n^ 3 = [ n ( n + 1 )/2 ​ ]^ 2 For n = 10 : = 2 [ 10 ( 11 )/2 ​ ]^ 2 = 2 ( 55 )^ 2 = 2 × 3025 6050 Last updated 27-07-2026 by NA ​

Explanation Given: x + y = 16 x-y=3 x − y = 3 Using the identity: x 2 − y 2 = ( x + y ) ( x − y ) = 16 × 3 = 48 Last updated 27-07-2026 by NA ​

Explanation First, find HCF of 48 and 80: 48 = 2⁴ × 3 80 = 2⁴ × 5 So, HCF = 16 Therefore: 48P − 80 = 16 48P = 96 P = 2 Last updated 27-07-2026 by NA

Explanation The series is: 2 × 1^ 2 + 4 × 2^ 2 + 6 × 3^ 2 + ⋯ The 10th term is: 2 n × n 2^ = 2 n^ 3 For n=10 n = 10 : 2 ( 10 )^ 3 = 2 × 1000 = 2000 Last updated 26-07-2026 by NA ​

Explanation √4x-3=4 Squaring both sides: 4 x − 3 = 16 4 x = 19 x = 19 ​/4 = 4.75 Last updated 25-07-2026 by NA

Explanation The pattern alternates between +2 and ×2: 4 → 6 (+2) 6 → 12 (×2) 12 → 14 (+2) 14 → 28 (×2) 28 → 30 (+2) 30 → 60 (×2) Last updated 17 july 2026 by NA

Explanation 5 × 2 = 10 10 × 2 = 20 20 × 2 = 40 40 × 2 = 80 Last verified on 11-2026

Explanation Sweets for children = 80 × 15 = 1200 Sweets for youngsters = 10 × 25 = 250 Total sweets = 1200 + 250 = 1450 Last updated question by NS on 11 May 2026

Explanation Ratio boys : girls = 9 : 11 Total students = 80 Total parts = 9 + 11 = 20 Each part = 80 ÷ 20 = 4 Girls = 11 parts: 11 × 4 = 44 Last updated question NS on 10 MAY 2026

Explanation 50% of 75% of 200: 75% of 200 = 150 50% of 150 = 75

Explanation 70% of 200 = 140

Explanation Series: 6, 3, 12, 6, 24, ___ Step 1: Find a pattern 6 → 3 (÷2) 3 → 12 (×4) 12 → 6 (÷2) 6 → 24 (×4) So the pattern alternates: ÷2, ×4, ÷2, ×4, ... Step 2: Next term 24 ÷ 2 = 12 Last updated by NA on 25-April-2026

Explanation Sequence: 2, 1, 3, 4, 7, 11, ? Observe the pattern: Each term is the sum of the previous two terms 2 + 1 = 3 1 + 3 = 4 3 + 4 = 7 4 + 7 = 11 7 + 11 = 18

Explanation Profit = Revenue − Cost Revenue = $5000, Cost = $3500 Profit = 5000 − 3500 = 1500

Explanation 2 + 3 = 5 5 + 7 = 12 12 + 11 = 23 23 + 15 = 38 38 + 19 = 57 57 + 23 = 80 Last verified on 31-03-2026

Explanation 20% means 20 out of 100 Formula: Number x 20 / 100 Step 1: 6440 x 20 = 128800 Step 2: 128800 / 100 = 1288 Last verified on 15-07-2026

Explanation Let the cost price (CP) = 100 (for easy calculation) Selling price (SP) = triple the CP = 3 × 100 = 300 Profit = SP − CP = 300 − 100 = 200 Profit Percentage = (Profit ÷ Cost Price) × 100 = (200 ÷ 100) × 100 = 200% Last updated 05-03-2026

Explanation Wait check: sequence = 1, 3, 5, 7, 11 Differences : 3 − 1 = 2 5 − 3 = 2 7 − 5 = 2 11 − 7 = 4 Question updated 03-March-2026