Cecilia Wangari is a great-grandmother who works in a shop in Kenya's capital, Nairobi, installing car stereos.

She reckons she is 78 years old - and started the business herself.

It's a family affair and she told her son to learn how to fix and repair the car stereos. She then learnt how to do it by watching him work.

Video journalist: Njoroge Muigai