If a profit of ₹200 is made on a book by selling at 20% profit, what is the selling price?
A ₹1000
B ₹1200
C ₹1400
D ₹1500
Explanation:
Profit = 20% of CP; ₹200 = 0.2×CP; CP = ₹1000; SP = 1000 + 200 = ₹1200
Three bells ring at 8, 12, and 18-minute intervals. After how many minutes will they ring together if they start together?
A 36 minutes
B 48 minutes
C 60 minutes
D 72 minutes
Correct Answer:
D. 72 minutes Explanation:
LCM(8, 12, 18) = LCM(2³, 2²×3, 2×3²) = 2³×3² = 8×9 = 72 minutes
The HCF of two numbers is 12 and their LCM is 180. If one number is 36, find the other number.
Explanation:
Using HCF × LCM = Product of two numbers. 12 × 180 = 36 × x. Therefore x = 2160/36 = 60
Three numbers are in the ratio 2:3:4 and their LCM is 240. Find the HCF of these numbers.
Explanation:
Let numbers be 2k, 3k, 4k. LCM(2k, 3k, 4k) = 12k = 240, so k = 20. HCF = k = 20
A product's cost price is ₹500. A trader marks it 60% above cost price and gives a discount of 25%. If HCF of profit and marked price is calculated, find the profit percentage.
Explanation:
MP = 500 × 1.60 = ₹800. SP = 800 × 0.75 = ₹600. Profit = 100. Profit% = (100/500) × 100 = 20%
HCF of two numbers is 11 and their sum is 99. If one number is 33, find the other number.
Explanation:
If HCF = 11, both numbers are multiples of 11. Sum = 99, one number = 33. Other = 99 - 33 = 66. Check: HCF(33,66) = 33. Correction: Numbers are 11×3=33 and 11×6=66. HCF = 11 ✓
The LCM of two coprime numbers is 143. If one number is 11, find the other.
Explanation:
For coprime numbers, HCF = 1. So LCM = Product. 143 = 11 × x. Therefore x = 13. Check: HCF(11,13) = 1 ✓
A train 250 meters long passes a platform 150 meters long in 20 seconds. Find the speed of the train.
A 54 km/h
B 64.8 km/h
C 72 km/h
D 90 km/h
Correct Answer:
C. 72 km/h Explanation:
Total distance = 250 + 150 = 400 meters. Time = 20 seconds. Speed = 400/20 = 20 m/s = 20 × 18/5 = 72 km/h
A person borrows ₹25,000 at 8% SI. After 3 years, how much total amount must he repay?
A ₹31,000
B ₹31,500
C ₹32,000
D ₹33,000
Correct Answer:
A. ₹31,000 Explanation:
SI = (25000 × 8 × 3)/100 = ₹6000. Total = 25000 + 6000 = ₹31,000
The HCF and LCM of two numbers are 15 and 360 respectively. If one number is 45, find the other number.
Explanation:
Using formula: HCF × LCM = Product of two numbers. 15 × 360 = 45 × x. Therefore x = 5400/45 = 120
