a is twice as fast as b . if b alone can do a piece of work in 10 days , in what time can a and b together complete the work ?
"a can do the work in 10 / 2 i . e . , 5 days . a and b ' s one day ' s work = 1 / 5 + 1 / 10 = ( 2 + 1 ) / 10 = 10 / 3 so a and b together can do the work in 10 / 3 days . answer : a"
inverse(add(divide(const_1, 10), multiply(divide(const_1, 10), const_2)))