2. Two Ultramen are fighting a monster, which can withstand 100 attacks. One of the Ultramen can attack 12 times per minute, and the other can attack 8 times per minute. If the two Ultramen start attacking together, they can defeat the monster in $\qquad$ minutes.
Answer: 5
Key Point: Application of Addition, Subtraction, Multiplication, and Division
Analysis: Two Ultramen together can attack $12+8=20$ (times) per minute. Therefore, it will take $100 \div 20=5$ (minutes) in total.