Problem: albert is 2 times mary ’ s age and 4 times as old as betty . mary is 12 years younger than albert . how old is betty ?
Rationale: "a = 2 m = m + 12 m = 12 a = 24 a = 4 b , and so b = 6 the answer is a ."
annotated_formula: divide(multiply(2, 12), 4)