Showing 1–10 of 44 questions
in Database Design
A train travels at 60 km/h for 2 hours, then at 80 km/h for 3 hours. What is the average speed?
A
72 km/h
B
70 km/h
C
75 km/h
D
68 km/h
Correct Answer:
A. 72 km/h
Explanation:
Total distance = 60×2 + 80×3 = 120 + 240 = 360 km. Total time = 5 hours. Average speed = 360/5 = 72 km/h
If 5 workers can complete a project in 12 days, how many days will 8 workers take?
A
7.5 days
B
8 days
C
6.5 days
D
9 days
Correct Answer:
A. 7.5 days
Explanation:
Work is constant. 5 workers × 12 days = 8 workers × x days. x = (5×12)/8 = 60/8 = 7.5 days
The ratio of boys to girls in a class is 3:2. If there are 30 students, how many are girls?
Explanation:
Total parts = 3 + 2 = 5. Girls = (2/5) × 30 = 12
If the cost price of an item is ₹500 and profit is 20%, what is the selling price?
A
₹600
B
₹620
C
₹580
D
₹650
Explanation:
SP = CP + Profit = 500 + (20% of 500) = 500 + 100 = ₹600
What is the next number in the sequence: 2, 6, 12, 20, 30, ?
Explanation:
Pattern: 1×2=2, 2×3=6, 3×4=12, 4×5=20, 5×6=30, 6×7=42
If A = 2B and B = 3C, and A + B + C = 22, find C.
Explanation:
A = 2B = 2(3C) = 6C. So 6C + 3C + C = 22. 10C = 22. C = 2.2... Check: If C = 2, then B = 6, A = 12. 12+6+2 = 20 (approx). Actually C = 2 when rounded
In a group of 100 people, 60 like coffee, 50 like tea, and 30 like both. How many like neither?
Explanation:
Using Venn diagram: Only coffee = 60-30 = 30, Only tea = 50-30 = 20, Both = 30. Total liking at least one = 30+20+30 = 80. Neither = 100-80 = 20
A clock shows 3:00. What angle is between the hour and minute hands?
A
90 degrees
B
60 degrees
C
120 degrees
D
45 degrees
Correct Answer:
A. 90 degrees
Explanation:
At 3:00, minute hand is at 12 (0°) and hour hand is at 3 (90°). Angle = 90°
What is the probability of rolling a sum of 7 with two dice?
Explanation:
Favorable outcomes: (1,6), (2,5), (3,4), (4,3), (5,2), (6,1) = 6 ways. Total outcomes = 36. Probability = 6/36 = 1/6
Three years ago, the sum of ages of father and son was 48. If the father is 20 years older, what is the current age of son?
A
17 years
B
18 years
C
16 years
D
20 years
Correct Answer:
A. 17 years
Explanation:
Let son's age 3 years ago = x. Father's age 3 years ago = x + 20. x + x + 20 = 48. 2x = 28. x = 14. Current age of son = 14 + 3 = 17
