The task is to generate the correct answer for a given math problem.

Problem: a train running at the speed of 70 km / hr crosses a pole in 9 sec . what is the length of the train ?
175 m

Problem: a and b can together finish a work in 40 days . they worked together for 10 days and then b left . after another 15 days , a finished the remaining work . in how many days a alone can finish the job ?
2

Problem: salad dressing p is made up of 30 % vinegar and 70 % oil , and salad dressing q contains 10 % vinegar and 90 % oil . if the two dressings are combined to produce a salad dressing that is 18 % vinegar , dressing p comprises what percentage of the new dressing ?
40 %