A book is bought for $60 and sold for $78

A book is bought for $60 and sold for $78. What is the profit in percentage?

This problem repeats another one in the library (at most with different numbers), so it's left out of browsing.

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #73209