Mathematics
Average / Arithmetic Mean
A car travels 120 km at 54 km/h and then 80 km at an unknown speed. Its overall average is 62.31 km/h. Find the second speed.
A. 79 km/h
B. 83 km/h
C. 81 km/h
D. 85 km/h
Correct Answer: C
Use 200/62.31 = 120/54 + 80/v. Solving gives v=81 km/h.
Mathematics
Average / Arithmetic Mean
A car travels 120 km at 52 km/h and then 80 km at an unknown speed. Its overall average is 60 km/h. Find the second speed.
A. 78 km/h
B. 76 km/h
C. 82 km/h
D. 80 km/h
Correct Answer: A
Use 200/60 = 120/52 + 80/v. Solving gives v=78 km/h.
Mathematics
Average / Arithmetic Mean
A car travels 120 km at 50 km/h and then 80 km at an unknown speed. Its overall average is 57.69 km/h. Find the second speed.
A. 75 km/h
B. 73 km/h
C. 77 km/h
D. 79 km/h
Correct Answer: A
Use 200/57.69 = 120/50 + 80/v. Solving gives v=75 km/h.
Mathematics
Average / Arithmetic Mean
A car travels 120 km at 48 km/h and then 80 km at an unknown speed. Its overall average is 55.38 km/h. Find the second speed.
A. 72 km/h
B. 76 km/h
C. 70 km/h
D. 74 km/h
Correct Answer: A
Use 200/55.38 = 120/48 + 80/v. Solving gives v=72 km/h.
Mathematics
Average / Arithmetic Mean
A car travels 120 km at 46 km/h and then 80 km at an unknown speed. Its overall average is 53.08 km/h. Find the second speed.
A. 69 km/h
B. 67 km/h
C. 71 km/h
D. 73 km/h
Correct Answer: A
Use 200/53.08 = 120/46 + 80/v. Solving gives v=69 km/h.
Mathematics
Average / Arithmetic Mean
A car travels 120 km at 44 km/h and then 80 km at an unknown speed. Its overall average is 50.77 km/h. Find the second speed.
A. 70 km/h
B. 68 km/h
C. 64 km/h
D. 66 km/h
Correct Answer: D
Use 200/50.77 = 120/44 + 80/v. Solving gives v=66 km/h.
Mathematics
Average / Arithmetic Mean
A car travels 120 km at 42 km/h and then 80 km at an unknown speed. Its overall average is 48.46 km/h. Find the second speed.
A. 65 km/h
B. 67 km/h
C. 61 km/h
D. 63 km/h
Correct Answer: D
Use 200/48.46 = 120/42 + 80/v. Solving gives v=63 km/h.
Mathematics
Average / Arithmetic Mean
A car travels 120 km at 40 km/h and then 80 km at an unknown speed. Its overall average is 46.15 km/h. Find the second speed.
A. 58 km/h
B. 62 km/h
C. 60 km/h
D. 64 km/h
Correct Answer: C
Use 200/46.15 = 120/40 + 80/v. Solving gives v=60 km/h.
Mathematics
Average / Arithmetic Mean
A bus travels for 1 hour at 48 km/h, 2 hours at 68 km/h, and 3 hours at 88 km/h. What is its average speed?
A. 72.67 km/h
B. 74.67 km/h
C. 76.67 km/h
D. 78.67 km/h
Correct Answer: B
Time-weighted average speed = (48+2×68+3×88)/6 = 74.67 km/h.
Mathematics
Average / Arithmetic Mean
A bus travels for 1 hour at 46 km/h, 2 hours at 66 km/h, and 3 hours at 86 km/h. What is its average speed?
A. 70.67 km/h
B. 74.67 km/h
C. 76.67 km/h
D. 72.67 km/h
Correct Answer: D
Time-weighted average speed = (46+2×66+3×86)/6 = 72.67 km/h.
Mathematics
Average / Arithmetic Mean
A bus travels for 1 hour at 44 km/h, 2 hours at 64 km/h, and 3 hours at 84 km/h. What is its average speed?
A. 74.67 km/h
B. 72.67 km/h
C. 70.67 km/h
D. 68.67 km/h
Correct Answer: C
Time-weighted average speed = (44+2×64+3×84)/6 = 70.67 km/h.
Mathematics
Average / Arithmetic Mean
A bus travels for 1 hour at 42 km/h, 2 hours at 62 km/h, and 3 hours at 82 km/h. What is its average speed?
A. 72.67 km/h
B. 66.67 km/h
C. 68.67 km/h
D. 70.67 km/h
Correct Answer: C
Time-weighted average speed = (42+2×62+3×82)/6 = 68.67 km/h.
Mathematics
Average / Arithmetic Mean
A bus travels for 1 hour at 40 km/h, 2 hours at 60 km/h, and 3 hours at 80 km/h. What is its average speed?
A. 70.67 km/h
B. 68.67 km/h
C. 66.67 km/h
D. 64.67 km/h
Correct Answer: C
Time-weighted average speed = (40+2×60+3×80)/6 = 66.67 km/h.
Mathematics
Average / Arithmetic Mean
A bus travels for 1 hour at 38 km/h, 2 hours at 58 km/h, and 3 hours at 78 km/h. What is its average speed?
A. 62.67 km/h
B. 66.67 km/h
C. 64.67 km/h
D. 68.67 km/h
Correct Answer: C
Time-weighted average speed = (38+2×58+3×78)/6 = 64.67 km/h.
Mathematics
Average / Arithmetic Mean
A bus travels for 1 hour at 36 km/h, 2 hours at 56 km/h, and 3 hours at 76 km/h. What is its average speed?
A. 60.67 km/h
B. 62.67 km/h
C. 64.67 km/h
D. 66.67 km/h
Correct Answer: B
Time-weighted average speed = (36+2×56+3×76)/6 = 62.67 km/h.
Mathematics
Average / Arithmetic Mean
A bus travels for 1 hour at 34 km/h, 2 hours at 54 km/h, and 3 hours at 74 km/h. What is its average speed?
A. 64.67 km/h
B. 62.67 km/h
C. 58.67 km/h
D. 60.67 km/h
Correct Answer: D
Time-weighted average speed = (34+2×54+3×74)/6 = 60.67 km/h.
Mathematics
Average / Arithmetic Mean
A bus travels for 1 hour at 32 km/h, 2 hours at 52 km/h, and 3 hours at 72 km/h. What is its average speed?
A. 60.67 km/h
B. 62.67 km/h
C. 58.67 km/h
D. 56.67 km/h
Correct Answer: C
Time-weighted average speed = (32+2×52+3×72)/6 = 58.67 km/h.
Mathematics
Average / Arithmetic Mean
A bus travels for 1 hour at 30 km/h, 2 hours at 50 km/h, and 3 hours at 70 km/h. What is its average speed?
A. 58.67 km/h
B. 60.67 km/h
C. 54.67 km/h
D. 56.67 km/h
Correct Answer: D
Time-weighted average speed = (30+2×50+3×70)/6 = 56.67 km/h.
Mathematics
Average / Arithmetic Mean
A car covers 190 km at 58 km/h and then 240 km at 78 km/h. Find the average speed for the entire trip.
A. 71.69 km/h
B. 65.69 km/h
C. 67.69 km/h
D. 69.69 km/h
Correct Answer: C
Average speed = 430/(190/58+240/78) = 67.69 km/h.
Mathematics
Average / Arithmetic Mean
A car covers 180 km at 56 km/h and then 230 km at 76 km/h. Find the average speed for the entire trip.
A. 67.7 km/h
B. 69.7 km/h
C. 65.7 km/h
D. 63.7 km/h
Correct Answer: C
Average speed = 410/(180/56+230/76) = 65.7 km/h.