Question

Ndiba left the hardware store and drove toward the train station. Willie left one hour later driving 10 mph faster in an effort to catch up to him. After three hours Willie finally caught up. What was Ndiba's average speed?

Answer 1

• Total timeof Ndiba =1+3=4hours

$\boxed{\sf Distance=Speed(Time)}$

Let

• Ndibas speed be x
• Willies speed=x+10

Both travelled same distance

$\\ \sf\longmapsto 4x=3(x+10)$

$\\ \sf\longmapsto 4x=3x+30$

$\\ \sf\longmapsto x=30mph$