I need this worked out in steps.  The following frequency distribution shows the distribution of delivery times (in days) for swimstuff.com customer orders during the last month.  How many orders were delivered from 1 day up to 3 days?

Delivery times in Days          Frequency

0-1                                              150

1-2                                                60

2-3                                                45

3-4                                                 30

4-5                                                 10

5-6                                                    5