Answer: I believe 140
Step-by-step explanation: This is how I found my answer:
420 / 3
= 140
420-140
= 280
420= number of all tickets sold.
140= number of adult tickets sold
280= number of student tickets sold
You might wonder how I know why it's 140. I know it's 140, because using my context clues, it stated:
"the number of student tickets sold was three times the number of adult tickets."
So, the one that was the bigger amount must be the student's tickets sold, while the lower amount has to be the adult's tickets sold. I hope this helped!