Grandma's Birthday

Alice and Jessica are writing invitations for a surprise birthday party for their grandmother. Alice starts at 8:00 a.m. and writes 10 invitations per hour. Jessica starts at 10:00 a.m. and writes 15 invitations per hour.

1. If the girls stop when they have written the same number of invitations, what time will it be?
2. Together, how many invitations will they have written?
3. Each invitation is for two people. Two-thirds of the people who receive invitations attend the party. Remembering that Alice and Jessica do not get invitations but are the hostesses, and Grandmother does not receive an invitation because she is the guest of honor, how many people are at the party?

Very Nicely done for a first POW!!!  Here is the solution.  It will clearify the answer for some of you and fine tune some of your thinking.  Again, nice job!!!

You could have made a table with the time and the number of invitations each girl made per hour. By 10:00, Alice will have done 20 invitations. At 11:00, 30 and 15 invitations will be produced by Alice and Jessica respectively. At 12:00, Alice would have completed 40 and Jessica would have done 30. At 1:00, 50 and 45 will be done. At 2:00, they will have both done 60 invitations for a total of 120 invitations. 2/3rds of the people invited would be 160 people in attendance. But don’t forget you need include Alice, Jessica and their Grandmother so there would be a total of 163 people at the party.

Ms. L.