Problem: a can complete a work in 15 days and b can do the same work in 9 days . if a after doing 5 days , leaves the work , find in how many days b will do the remaining work ?
Rationale: "the required answer = ( 15 - 5 ) * 9 / 15 = 40 / 10 = 6 days answer is c"
annotated_formula: add(multiply(15, 5), divide(15, 5))