1. "Look at this invoice from Kellers," said Ross. "It's obviously wrong, but do you see what they've done?" Lexi looked. "Of course, I've got it," she replied. "They interchanged pounds and pence, making it just 7p less than three times what it should be. A careless mistake." She was right, so what was the correct amount?

13 pounds 40 pence

15 pounds 60 pence

14 pounds 30 pence