Jenny had driven for 2 h at a constant speed when round repairs forced her to reduce her speed by 10 mi/h for the remaining 1 h of her 152 mi trip. Find her original speed.

Her original speed is 54 mi/h

Step-by-step explanation:

Here, we want to calculate the original speed

Let this be x mi/h

Mathematically;

distance = speed * time

So she drove at a speed of x mi/h for 2 hours, then (x-10) mi/h for the remaining 1 hour for a total 152 mi journey

Mathematically, we can add up the journey parts as

x(2) + (x-10)1 = 152

2x + x - 10 = 152

3x = 152 + 10

3x = 162

x = 162/3

x = 54 mi/h