Anwen walks at an average speed of 3 km/h for 2 hours
20 minutes. How far has Anwen
walked?

7 km

Step-by-step explanation:

2 hours 20 minutes is 2 and 1/3 hours. 3 * 2 and 1/3 = 3 * 7/3 = 7km.

7 km

Step-by-step explanation:

In 1 hour, he did 3 km

In 2 hours, he will do 6 km

20 minutes = 20/60 = 1/3

In 20 minutes, he will do 1/3 x 3 = 1 km

So total distance travelled = 7 km

f(x) has value 150 at x= 0

and 0 at x= 3

so d(f(x))/dt = slope = -150/3 = -50