Math Flashcards
7 cards from real AMCAT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Math flashcards as text
The ratio of boys to girls in a class is 3:4. If there are 28 girls, how many students are in the class?
Answer: 49
If 4 parts = 28, then 1 part = 7; total parts = 7, so total students = 7 × 7 = 49.
A shopkeeper bought an item for $240 and sold it at a 25% profit. What was the selling price?
Answer: $300
Selling price = 240 × 1.25 = $300.
What is the value of √(0.0081)?
Answer: 0.09
√(0.0081) = √(81/10000) = 9/100 = 0.09.
If a car depreciates at 10% per year, what is its value after 2 years if it originally cost $20,000?
Answer: $16,200
Value = 20000 × (0.9)² = 20000 × 0.81 = $16,200.
Find the HCF of 48, 72, and 96.
Answer: 24
Prime factorization: 48=2⁴×3, 72=2³×3², 96=2⁵×3; HCF = 2³×3 = 24.
A pipe can fill a tank in 6 hours and another pipe can drain it in 8 hours. If both are open simultaneously, how long to fill the tank?
Answer: 24 hours
Net rate = 1/6 - 1/8 = 4/24 - 3/24 = 1/24 per hour; tank fills in 24 hours.
If 3 men can complete a job in 12 days, how many days will 4 men take to complete the same job?
Answer: 9 days
Total work = 3 × 12 = 36 man-days; with 4 men: 36/4 = 9 days.