Lizzy: There are 19 students in the 3rd grade and twice that number in the 4th grade. There are 10 boys and 19 girls in the 2nd grade. How many students are there in total?.
Me: Hmmm, let me think. I think this is the detailed solution:
In the third grade, there are 19 students. In the fourth grade, there are 2 × 19 = 38 students. Counting the boys and girls in the second grade, there are 10 + 19 = 29. There are 19 + 38 + 29 = 86 students in total. Final answer: 86.