A person travel from A to B at a constant speed v = 4 km / h. After he travelling \(\frac{2}{3}\) of the distance, he speed up 25% velocities. It takes 28 minutes to go A to B. The length of AB is.....
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Mr.Joseph drives car from A to B at a constant speed. If the speed of the car is increased by 20%, it takes him one hour less than the usual time. If he drives at the constant speed for the first 100km before increasing the speed by 30%, it also takes him one hour less than the usual. The distance of AB is ..........km.
Gọi S là quãng đường
v là vận tốc
t là thời gian Mr.J đi thường ngày
=>\(\dfrac{S}{120\%v}=t-1\)
\(\dfrac{100}{v}+\dfrac{S-100}{130\%v}=t-1\)
=>\(\dfrac{S}{120\%v}=\dfrac{100}{v}+\dfrac{S-100}{130\%v}\)
<=>\(\dfrac{130S}{156v}=\dfrac{15600+120S-12000}{156v}\)
<=>\(10S=3600\)
<=>\(S=360\)
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At 8:24 AM,a motorbike travels from A to B at a speed of 36 km/h.At 9:00 AM,a car travels from A to B at a speed of 54km/h and is able to catch up with the motorbike at B.Find the distance from A to B in kilometers.
Dịch : Lúc 8 giờ 24 phút,một chiếc xe máy đi từ A đến B với vận tốc 36 km/h.Lúc 9 giờ,một chiếc ô tô đi từ A đến B với vận tốc 54 km/h và đuổi kịp xe máy tại B.Quãng đường AB dài bao nhiêu km ?
Giải : Xe máy đi trước ô tô : 9 giờ - 8 giờ 24 phút = 36 phút = 0,6 giờ
Khi ô tô khởi hành thì 2 xe cách nhau : 36 x 0,6 = 21,6 (km)
Hiệu vận tốc 2 xe là : 54 - 36 = 18 (km/h)
Ô tô đuổi kịp xe máy sau : 21,6 : 18 = 1,2 (giờ)
Quãng đường AB là : 54 x 1,2 = 64,8 (km)
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Thời gian xe máy đi trước ô tô là:
9 giờ - 8 giờ 24 phút = 36( phút )
Đổi : 36 phút = 0,6 giờ
Khi ô tô khởi hành thì 2 xe cách nhau là:
36 x 0,6 = 21,6 ( km )
Sau mỗi giờ , ô tô đi hơn xe máy là:
54 - 36 = 18 ( km )
Thời gian ô tô đuổi kịp xe máy là:
21,6 : 18 = 1,2 ( giờ )
Quãng đường AB dài là:
54 x 1,2 = 64,8 ( km )
Đáp số: 64,8 km
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Question 1Bob drove from City P to City Q. He traveled the first 36km at an average speed of 54km/h. He traveled the remaining 96km at a average speed of 72km/h. Find his average speed for the whole trip.Answer: km/h.Question 2John drove from Town A to Town B in 5 hours. His average speed for the first 3.5 hours was 64km/h. His average speed for the last 1.5 hours was 60km/h. What was the total distance he traveled? Answer: km.Question 3A car traveled at 50km/h for 2 hours and at 60km/h for 3 ho...
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Question 1
Bob drove from City P to City Q. He traveled the first 36km at an average speed of 54km/h. He traveled the remaining 96km at a average speed of 72km/h. Find his average speed for the whole trip.
Answer: km/h.
Question 2
John drove from Town A to Town B in 5 hours. His average speed for the first 3.5 hours was 64km/h. His average speed for the last 1.5 hours was 60km/h. What was the total distance he traveled?
Answer: km.
Question 3
A car traveled at 50km/h for 2 hours and at 60km/h for 3 hours. What is the car’s average speed?
Answer: km/h
Question 1:66 km/h
Question 2:314 km
Question 3:200/9 km/h
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Question 1:66 km/h
Question 2:314 km
Question 3:56 km/h
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6 tháng 1 2022 lúc 6:13
The route AB is 60km long. At 7 am, one motorbike travels from A to B with a constant speed. When this motorbike reaches B, it returns to A immediately with the speed increase by 10km/h and reaches A at 10.30 am at the same day. What is the original speed of this motorbike?
Note: You must write your answer in English.
Note: You must write your answer in English.
Exchange 2h30' = 2.5h
Let the real speed of the canoe be x (km/h) (x > 0)
=> Speed downstream: x + 8 (km/h)
Upstream speed: x-8 (km/h)
According to the arle we have (x+8).2 = (x-8).2.5 => 2x+16 = 2.5x - 20 => 0.5x = 36 => x = 72 (km/h)
=> distance from A to B = (72+8).2 = 160km
Mark rides bicycle from his house to school with a speed of 15 km/h and arrives at the school 20 minutes late. However, if he rides with 20 km/h, he would reach the school only 5 minute late. Find the distance between his house and the school.
Answer: The distance between his house and the school is ........... km.
At 7 hours and 30 minutes, an automobile going from A to B, to 11 hours, the cars arrive. The speed of the cars is 60km / h. Calculate the distance AB
Are you sure about ' cars' in the problem. However, I can show you in case the problem can be true.
The car spends 11h-7h30min= 3h30min to go from A to B.
Since the speed of car is 60 km/h.
Applying the operation s=vt, we have
The distance AB=s= 60 × 3h30min= 210km.
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Mr. Bao goes from home to the stadium and the distance is 140 km. He rode his bicycle for 1 hour and 20 minutes and then proceeded by car 2 hours to arrive. Knowing the speed of cars folds the motor speed 4 times. Calculate the speed of each vehicle.
David walks to a shoppingmall tomeet his friend.If he walks at a speed of 30 meters per minutes,he will be late 4 minutes.If he speeds up to 40 meters perminutes,he will reach the shopping mall 3 minutes nefore the appoint time.How far away is the shopping mall from his place?
So from his place to the shopping mall with the number of kilometers is :
30 x 4 = 120 ( kilometers )
or : 40 x 3 = 120 ( kilometers )
Answer : 120 kilometers
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If Ben cycles from Town A to Town B at a speed of 10 km/h, he will arrive at 10 a.m. If he travels at 15 km/h, he will arrive at 8 a.m. At what speed must he cycle to arrive at 9 a.m.?
Write down the answer in km/h.
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