Yasmine Saleh certainly knows how to use a credit card. A 22-year-old university student, Yasmine got her first credit card on her 18th birthday and has had one ever since. “My parents wanted me to have a card for emergency situations or for when I need to make big purchases,” she said. Though her parents have not given her specific limits, she says that they expect her to buy things “within reason.” “I don’t think I spend that much — sometimes when I go shopping I get a couple thousand pounds...