Quantitative Techniques Flashcards

A train travels 360 km in 4 hours. What is its speed in km/h?

Answer: 90

Speed = Distance / Time = 360 / 4 = 90 km/h.

If the simple interest on $5,000 at 8% per annum for 3 years is calculated, what is the amount?

Answer: $6,200

SI = (5000 × 8 × 3) / 100 = $1,200; Amount = 5000 + 1200 = $6,200.

What is the compound interest on $10,000 at 10% per annum for 2 years?

Answer: $2,100

CI = 10000 × [(1.1)² − 1] = 10000 × 0.21 = $2,100.

A shopkeeper marks a product 25% above cost price and gives a 10% discount. What is the profit percentage?

Answer: 12.5%

Selling price = 1.25 × 0.90 = 1.125 times cost, giving 12.5% profit.

Two pipes can fill a tank in 12 hours and 18 hours respectively. How long will they take together?

Answer: 7.2 hours

Combined rate = 1/12 + 1/18 = 5/36; Time = 36/5 = 7.2 hours.

The ratio of ages of A and B is 3:5. Six years later, their ratio will be 2:3. What is B's current age?

Answer: 30

Let ages be 3x and 5x; (3x+6)/(5x+6) = 2/3 gives x = 6, so B = 30.