A train travels 120 km in 2 hours and then 80 km in 1.5 hours. What is the average speed of the entire journey?
A
65.71 km/h
B
70 km/h
C
60 km/h
D
75 km/h
Correct Answer:
A. 65.71 km/h
Explanation:
Total distance = 120 + 80 = 200 km. Total time = 2 + 1.5 = 3.5 hours. Average speed = 200/3.5 = 57.14 km/h. Wait, let me recalculate: 200/3.5 = 65.71 km/h.
If a number is increased by 20% and then decreased by 20%, what is the net change?
A
No change
B
4% decrease
C
4% increase
D
2% decrease
Correct Answer:
B. 4% decrease
Explanation:
Let the number be 100. After 20% increase: 120. After 20% decrease of 120: 120 × 0.8 = 96. Net change = 96 - 100 = -4, which is 4% decrease.
A merchant bought goods for Rs. 400 and marked them at 40% above the cost price. He gave a 10% discount. What is his profit percentage?
Explanation:
Cost price = 400. Marked price = 400 × 1.40 = 560. Selling price = 560 × 0.90 = 504. Profit = 504 - 400 = 104. Profit % = (104/400) × 100 = 26%.
If 5 men can do a work in 12 days, how many men are needed to do the same work in 3 days?
A
15 men
B
20 men
C
25 men
D
30 men
Correct Answer:
B. 20 men
Explanation:
Work = 5 × 12 = 60 man-days. For 3 days: Men needed = 60/3 = 20 men.
What is the LCM of 24, 36, and 48?
Explanation:
24 = 2^3 × 3, 36 = 2^2 × 3^2, 48 = 2^4 × 3. LCM = 2^4 × 3^2 = 16 × 9 = 144.
A person invests Rs. 10,000 at 10% per annum for 2 years. What is the compound interest?
A
Rs. 2,000
B
Rs. 2,100
C
Rs. 2,050
D
Rs. 1,950
Correct Answer:
B. Rs. 2,100
Explanation:
CI = P(1+R/100)^T - P = 10000(1.1)^2 - 10000 = 10000(1.21) - 10000 = 12100 - 10000 = 2100.
Find the odd one out: 12, 24, 36, 48, 62
Explanation:
12, 24, 36, 48 are all multiples of 12. 62 is not a multiple of 12.
A clock shows 3:00. What is the angle between the hour and minute hands?
Explanation:
At 3:00, the minute hand is at 12 and hour hand is at 3. Each hour represents 30° (360°/12). Angle = 3 × 30° = 90°.
If x^2 + 5x + 6 = 0, what are the roots?
A
-2 and -3
B
2 and 3
C
-1 and -6
D
1 and 6
Correct Answer:
A. -2 and -3
Explanation:
x^2 + 5x + 6 = (x+2)(x+3) = 0. So x = -2 or x = -3.
What is 25% of 60% of 1000?
Explanation:
60% of 1000 = 600. 25% of 600 = 150.
