The science has got real and experiential attitudes toward the multitasking.First, psychologists informed about multitasking could give distraction and delay for doing the activities properly form milliseconds up to 20 minutes.They argued that multitasking also could make mistakes in performance.You won't do the tasks as good as you do each of them separately. So, we need to focus on one task every time.It is not good to drive a car and talking on the phone.
However, other scientists see multitasking is not harmful as it seems to be because some studies show that exercising and listening to music may be beneficial.
Finally,there are two different attitudes about multitasking.One is against and the other says no problem.I myself will stand with the first.