Solve 5th-grade math problems Pages 69-70 VBT Volume 2, Focused Practice, Exercise 136

Solve 5th-grade math problems on pages 69 and 70 of VBT Volume 2, Focused Practice, Exercise 136, detailed solutions for exercises 1, 2, 3, and 4 closely aligned with the lesson content. Refer to understand the solution approach, compare with your own work, especially mastering how to solve problems related to uniform motion, time, and speed.

A person walks 14.8km in 3 hours and 20 minutes. Calculate the speed of the walker in m/minute.

- Convert the distance to meters.

- Convert the time to minutes.

- To calculate speed, divide the distance by the time.

Conversion: 3 hours 20 minutes = 200 minutes

14.8 kilometers equals 14800 meters

The speed of the pedestrian is:

14800 ÷ 200 = 74 (meters/minute)

Answer: 74 meters/minute.

A car and a motorcycle depart simultaneously from opposite ends of a distance and travel towards each other. After 2 hours 15 minutes, they meet. Knowing that the car travels at a speed of 54 km/h and the motorcycle travels at a speed of 38 km/h. Calculate the distance traveled.

- Convert: 2 hours 15 minutes = 2.25 hours.

- Calculate the distance the car travels = Car speed x time

- Calculate the distance the motorcycle travels = Motorcycle speed x time.

- Total distance = distance the car travels + distance the motorcycle travels (Because the two vehicles move in opposite directions)

Convert: 2 hours 15 minutes = 2.25 hours.

The distance the car travels in 2 hours 15 minutes is :

54 x 2.25 = 121.5 (km)

The distance the motorcycle travels in 2 hours 15 minutes is :

38 x 2.25 = 85.5 (km)

The length of that distance is :

121.5 + 85.5 = 207 (km)

The answer is: 207km.

A person walks the distance AB in 2 hours and 30 minutes at a speed of 4.2 km/h. If the person rides a bicycle at a speed equal to 5/2 times the walking speed, how long does it take to travel the aforementioned distance?

- Convert: 2 hours 30 minutes = 2.5 hours.

- The length of distance AB = walking speed x time.

- The speed of the person riding a bicycle = walking speed x 5/2.

- The time the person rides a bicycle to travel the distance AB = distance AB : speed of the person riding a bicycle

Convert: 2 hours 30 minutes = 2.5 hours

The length of distance AB is:

4.2 multiplied by 2.5 equals 10.5 (km)

The speed of the person riding the bicycle is:

4.2 multiplied by 5252 equals 10.5 (km/hour)

The time the person riding the bicycle travels the distance AB is:

10.5 divided by 10.5 equals 1 (hour)

Answer: 1 hour.

A car departs from city A at 10:35 and arrives at city B at 15:57. Along the way, the driver takes a lunch break for 1 hour 22 minutes. Knowing that the two cities are 180km apart, calculate the speed of the car.

- Find the time the car travels from A to B including the break = 15:57 - 10:35

- Actual driving time of the car = time the car has traveled including the break - lunch break time.

- Car speed = distance : actual driving time of the car

The time the car travels from city A to city B including the lunch break is :

15 hours 57 minutes - 10 hours 35 minutes = 5 hours 22 minutes

The time the car travels from city A to city B excluding the lunch break is :

5 hours 22 minutes - 1 hour 22 minutes = 4 hours

Car speed is :

180 : 4 = 45 (km/h)

Answer: 45 km/h.

You are currently viewing the guidance for solving 5th-grade math problems on pages 69 and 70 of VBT Volume 2, Concentrated Practice, including Exercise 136. You can review the guidance for solving 5th-grade math problems on pages 67 and 68 of VBT Volume 2, Concentrated Practice, or preview the guidance for solving 5th-grade math problems on pages 71 and 72 of VBT Volume 2, Concentrated Practice to understand more about the lesson.

Best wishes for your math studies.