human
Marla has to spend 20 minutes driving one way to her son's school, then 70 minutes attending parent-teacher night, then the same amount of time driving home. How many minutes does Marla spend on this errand in total?
assistant
How many minutes does Marla spend driving one way? ** First multiply Marla's one-way driving time by 2 to find her total driving time: 20 minutes * 2 = <<20*2=40>>40 minutes
How many minutes does Marla spend on this errand in total? ** Then add Marla's driving time to the time spent attending the conference to find the total time: 70 minutes + 40 minutes = <<70+40=110>>110 minutes
#### 110