Danny brings 3 watermelons to his family picnic. He cuts each watermelon into 10 slices. His sister brings 1 watermelon to the family picnic, and she cuts the watermelon into 15 slices. How many watermelon slices are there in total at the picnic?
From Danny, there are 3 * 10 = <<3*10=30>>30 watermelon slices
From his sister, there are 1 * 15 = <<1*15=15>>15 watermelon slices
There are a total of 30 + 15 = <<30+15=45>>45 watermelon slices
#### 45