ARITHMETIC QUESTIONS

A boat takes 4 hours to travel 40 km downstream and 5 hours to travel the

same distance upstream. What is the speed of the stream?

• 1 km/hr

• 5 km/hr

• 4km/hr

• 3 km/hr

Answer explanation

Solution

Let the speed of the boat in still water be x km/hr and the speed of the

stream be y km/hr.

Downstream speed = x + y = 40 / 4 = 10 km/hr

Upstream speed = x - y = 40 / 5 = 8 km/hr

Adding these equations: 2x = 18

x = 9 km/hr

Subtracting these equations: 2y = 2

y = 1 km/hr

Answer: A) 1 km/hr

A man sells a car for Rs. 2,50,000 at a loss of 20%. At what price should he

sell it to gain 20% profit?

• Rs. 3,00,000

• Rs. 3,12,500

• Rs. 3,50,000

• Rs. 3,75,000

Answer explanation

Solution

Let the cost price be x.

Selling price at 20% loss = x * 0.80 = 2,50,000

x = 2,50,000 / 0.80 = Rs. 3,12,500

To gain 20% profit, selling price = 3,12,500 * 1.20 = Rs. 3,75,000

Answer: D) Rs. 3,75,000

A sum of money doubles itself in 6 years at simple interest. What is the

rate of interest?

• 16%

• 18%

• 20%

• 24%

• None of these

Answer explanation

Let the principal be P and the interest be R% per annum.

Amount = 2P

Interest = Amount - Principal = P

P * R * 6 / 100 = P

R * 6 = 100

R = 100 / 6 ≈ 16.67%

Answer: E) None of these

If the price of sugar increases by 20% and a family reduces its

consumption by 25% to keep the expenditure the same, what is the

percentage decrease in the expenditure on sugar?

• 5%

• 10%

• 15%

• 20%

Answer explanation

Solution

Let the original price of sugar be Rs. 100 and original consumption be 100

kg.

Original expenditure = Rs. 100 * 100 kg = Rs. 10000

New price = Rs. 120 (20% increase)

New consumption = 75 kg (25% decrease)

New expenditure = Rs. 120 * 75 kg = Rs. 9000

Percentage decrease in expenditure = (10000 - 9000) / 10000 * 100 = 10%

Answer: B) 10%

A man spends 80% of his income. If his income increases by 25% and his

expenditure increases by 20%, what is the percentage increase in his

savings?

• 30%

• 35%

• 40%

• 45%

Answer explanation

Let the original income be Rs. 100.

Original expenditure = Rs. 80Original savings = Rs. 100 - Rs. 80 = Rs. 20

New income = Rs. 100 + 25% of Rs. 100 = Rs. 125

New expenditure = Rs. 80 + 20% of Rs. 80 = Rs. 96

New savings = Rs. 125 - Rs. 96 = Rs. 29

Percentage increase in savings = (29 - 20) / 20 * 100 = 45%

Answer: D) 45%

The average age of a group of 30 students is 14 years. If the teacher's age

is added, the average age increases by 1 year. What is the teacher's age?

• 40

• 45

• 50

• 55

Answer explanation

Solution

Total age of 30 students = 30 * 14 = 420 years

Average age after adding teacher's age = 15 years

Total age after adding teacher's age = 31 * 15 = 465 years

Teacher's age = 465 - 420 = 45 years

Answer: B) 45 years

A train 150 meters long is running at a speed of 60 km/hr. How long will it

take to pass a platform 200 meters long?

• 15 second

• 18 second

• 21 second

• 24 second

Answer explanation

Solution

Total distance to be covered = 150 meters + 200 meters = 350 meters

Speed of the train = 60 km/hr = (60 * 1000) / 3600 meters/second = 16.67

meters/second

Time = 350 / 16.67 ≈ 21 seconds

Answer: C) 21 seconds

A shopkeeper gives a discount of 10% on the marked price of an article

and still makes a profit of 20%. If the marked price is Rs. 1000, what is the

cost price of the article?

• Rs. 700

• Rs.750

• Rs.800

• Rs.850

Answer explanation

Solution

Marked price = Rs. 1000

Selling price after 10% discount = 1000 * 0.9 = Rs. 900

Let the cost price be x.

Selling price = Cost price + Profit

900 = x + 0.2x

900 = 1.2x

x = 900 / 1.2 = 750

Answer: B) Rs. 750

A cyclist covers a certain distance in 3 hours at a speed of 40 km/hr. What

would be his speed if he covers the same distance in 2 hours?

• 55km/hr

• 60km/hr

• 50km/hr

• 65km/hr

Answer explanation

Solution

Distance covered = 40 * 3 = 120 km

New speed = 120 / 2 = 60 km/hr

Answer: C) 60 km/hr

If a man walks at 8 km/hr, he misses a train by 10 minutes. However, if he

walks at 10 km/hr, he reaches the station 5 minutes before the train.

What is the distance to the station?

• 6 km

• 8 km

• 10 km

• 12 km

Answer explanation

Solution

Let the distance to the station be d km.

Time difference = 15 minutes = 1/4 hour

Using the information provided:

d / 8 = d / 10 + 1/4

d / 8 - d / 10 = 1/4

(5d - 4d) / 40 = 1/4

d / 40 = 1/4

d = 10 km

Answer: C) 10 km