Mathematics
Average / Arithmetic Mean
Six consecutive integers begin with 31. What is their average?
A. 32.5
B. 33.5
C. 34.5
D. 35.5
Correct Answer: B
Mean = (31+36)/2 = 33.5.
Mathematics
Average / Arithmetic Mean
Six consecutive integers begin with 28. What is their average?
A. 31.5
B. 30.5
C. 32.5
D. 29.5
Correct Answer: B
Mean = (28+33)/2 = 30.5.
Mathematics
Average / Arithmetic Mean
Six consecutive integers begin with 25. What is their average?
A. 27.5
B. 26.5
C. 29.5
D. 28.5
Correct Answer: A
Mean = (25+30)/2 = 27.5.
Mathematics
Average / Arithmetic Mean
Six consecutive integers begin with 22. What is their average?
A. 23.5
B. 25.5
C. 24.5
D. 26.5
Correct Answer: C
Mean = (22+27)/2 = 24.5.
Mathematics
Average / Arithmetic Mean
Six consecutive integers begin with 19. What is their average?
A. 22.5
B. 23.5
C. 21.5
D. 20.5
Correct Answer: C
Mean = (19+24)/2 = 21.5.
Mathematics
Average / Arithmetic Mean
Six consecutive integers begin with 16. What is their average?
A. 17.5
B. 18.5
C. 20.5
D. 19.5
Correct Answer: B
Mean = (16+21)/2 = 18.5.
Mathematics
Average / Arithmetic Mean
Six consecutive integers begin with 13. What is their average?
A. 15.5
B. 14.5
C. 17.5
D. 16.5
Correct Answer: A
Mean = (13+18)/2 = 15.5.
Mathematics
Average / Arithmetic Mean
Six consecutive integers begin with 10. What is their average?
A. 11.5
B. 14.5
C. 13.5
D. 12.5
Correct Answer: D
Mean = (10+15)/2 = 12.5.
Mathematics
Average / Arithmetic Mean
For a round trip over equal outward and return distances, the speeds are 54 km/h and 72 km/h. Calculate the journey's mean speed.
A. 61.71 km/h
B. 59.71 km/h
C. 63.71 km/h
D. 65.71 km/h
Correct Answer: A
Equal-distance mean speed = 2×54×72/(54+72) = 61.71 km/h.
Mathematics
Average / Arithmetic Mean
For a round trip over equal outward and return distances, the speeds are 52 km/h and 70 km/h. Calculate the journey's mean speed.
A. 59.67 km/h
B. 63.67 km/h
C. 61.67 km/h
D. 57.67 km/h
Correct Answer: A
Equal-distance mean speed = 2×52×70/(52+70) = 59.67 km/h.
Mathematics
Average / Arithmetic Mean
For a round trip over equal outward and return distances, the speeds are 50 km/h and 68 km/h. Calculate the journey's mean speed.
A. 57.63 km/h
B. 55.63 km/h
C. 61.63 km/h
D. 59.63 km/h
Correct Answer: A
Equal-distance mean speed = 2×50×68/(50+68) = 57.63 km/h.
Mathematics
Average / Arithmetic Mean
For a round trip over equal outward and return distances, the speeds are 48 km/h and 66 km/h. Calculate the journey's mean speed.
A. 53.58 km/h
B. 59.58 km/h
C. 55.58 km/h
D. 57.58 km/h
Correct Answer: C
Equal-distance mean speed = 2×48×66/(48+66) = 55.58 km/h.
Mathematics
Average / Arithmetic Mean
For a round trip over equal outward and return distances, the speeds are 46 km/h and 64 km/h. Calculate the journey's mean speed.
A. 53.53 km/h
B. 55.53 km/h
C. 57.53 km/h
D. 51.53 km/h
Correct Answer: A
Equal-distance mean speed = 2×46×64/(46+64) = 53.53 km/h.
Mathematics
Average / Arithmetic Mean
For a round trip over equal outward and return distances, the speeds are 44 km/h and 62 km/h. Calculate the journey's mean speed.
A. 55.47 km/h
B. 51.47 km/h
C. 49.47 km/h
D. 53.47 km/h
Correct Answer: B
Equal-distance mean speed = 2×44×62/(44+62) = 51.47 km/h.
Mathematics
Average / Arithmetic Mean
For a round trip over equal outward and return distances, the speeds are 42 km/h and 60 km/h. Calculate the journey's mean speed.
A. 49.41 km/h
B. 51.41 km/h
C. 53.41 km/h
D. 47.41 km/h
Correct Answer: A
Equal-distance mean speed = 2×42×60/(42+60) = 49.41 km/h.
Mathematics
Average / Arithmetic Mean
For a round trip over equal outward and return distances, the speeds are 40 km/h and 58 km/h. Calculate the journey's mean speed.
A. 49.35 km/h
B. 51.35 km/h
C. 45.35 km/h
D. 47.35 km/h
Correct Answer: D
Equal-distance mean speed = 2×40×58/(40+58) = 47.35 km/h.
Mathematics
Average / Arithmetic Mean
For a round trip over equal outward and return distances, the speeds are 38 km/h and 56 km/h. Calculate the journey's mean speed.
A. 47.28 km/h
B. 45.28 km/h
C. 43.28 km/h
D. 49.28 km/h
Correct Answer: B
Equal-distance mean speed = 2×38×56/(38+56) = 45.28 km/h.
Mathematics
Average / Arithmetic Mean
For a round trip over equal outward and return distances, the speeds are 36 km/h and 54 km/h. Calculate the journey's mean speed.
A. 47.2 km/h
B. 43.2 km/h
C. 45.2 km/h
D. 41.2 km/h
Correct Answer: B
Equal-distance mean speed = 2×36×54/(36+54) = 43.2 km/h.
Mathematics
Average / Arithmetic Mean
A car travels 120 km at 58 km/h and then 80 km at an unknown speed. Its overall average is 66.92 km/h. Find the second speed.
A. 89 km/h
B. 87 km/h
C. 91 km/h
D. 85 km/h
Correct Answer: B
Use 200/66.92 = 120/58 + 80/v. Solving gives v=87 km/h.
Mathematics
Average / Arithmetic Mean
A car travels 120 km at 56 km/h and then 80 km at an unknown speed. Its overall average is 64.62 km/h. Find the second speed.
A. 88 km/h
B. 84 km/h
C. 86 km/h
D. 82 km/h
Correct Answer: B
Use 200/64.62 = 120/56 + 80/v. Solving gives v=84 km/h.