Problem: a student got twice as many sums wrong as he got right . if he attempted 27 sums in all , how many did he solve correctly ?
Rationale: "explanation : suppose the boy got x sums right and 2 x sums wrong . then , x + 2 x = 27 3 x = 27 x = 9 . answer : d"
annotated_formula: divide(27, add(const_1, const_2))