Unit Conversions in Word Problems

Unit conversions are essential in solving various word problems in the SAT Math section. These problems often require you to convert one unit of measurement to another, ensuring you apply the correct conversion factors.

Explanation

To solve unit conversion problems, follow these steps:

1. Identify the unit you are converting from and the unit you need to convert to.
2. Find the appropriate conversion factor.
3. Multiply or divide using the conversion factor to find the answer.

Example Problem

Problem: A car travels 120 kilometers in 1.5 hours. What is the speed of the car in miles per hour (mph)?

Step 1: Identify the conversion needed. We need to convert kilometers to miles. The conversion factor is:

$$1 ext{ km} = 0.621371 ext{ miles}$$

Step 2: Calculate the speed in kilometers per hour (kph):

$$ext{Speed} = \frac{120 ext{ km}}{1.5 ext{ hours}} = 80 ext{ kph}$$

Step 3: Convert kph to mph:

$$ext{Speed in mph} = 80 ext{ kph} \times 0.621371 ext{ miles/km}$$

Step 4: Calculate:

$$= 80 \times 0.621371 \approx 49.70968 ext{ mph}$$

Thus, the speed of the car is approximately 49.71 mph.

Key Questions

• Convert 150 centimeters to inches.
• How many gallons are in 3 liters?
• A recipe calls for 2.5 kilograms of flour. How many pounds is that?
• If a runner completes a race in 10 kilometers, how many miles did they run?

Keywords

• Unit conversion
• Conversion factor
• Kilometers to miles
• Speed
• Measurement