If 2@3=8 and 3@4=15, rule a@b=a×b+1. Then 4@5=?
Question 1
Q1. If 2@3=8 and 3@4=15, rule a@b=a×b+1. Then 4@5=?
Answer: 21
Explanation: Four times five plus one equals twenty one. Work each step carefully; ISSB math rewards accuracy under time pressure.