The average speed of a car is 75 km/h. The driver first decreases its average speed by 40% and then increases it by 50%. What is the new average speed now?

Options

A. 67.5 km
B. 60 km
C. 90 km
D. 60.5 km

Answer

To find the new average speed of the car after the driver decreases it by 40% and then increases it by 50%, we can follow these steps:

### Step 1: Calculate the decreased speed
1. The original average speed of the car is 75 km/h.
2. The driver decreases the speed by 40%.
- To find 40% of 75 km/h:
\[ \text{Decrease} = \frac{40}{100} \times 75 = 30 \text{ km/h} \]
3. Now, subtract this decrease from the original speed:
\[ \text{New Speed after Decrease} = 75 - 30 = 45 \text{ km/h} \]

### Step 2: Calculate the increased speed
1. Now, the driver increases the new speed (45 km/h) by 50%.
- To find 50% of 45 km/h:
\[ \text{Increase} = \frac{50}{100} \times 45 = 22.5 \text{ km/h} \]
2. Add this increase to the decreased speed:
\[ \text{New Average Speed} = 45 + 22.5 = 67.5 \text{ km/h} \]

### Final Answer
The new average speed of the car is **67.5 km/h**.

---