Answer: He will have guitar lessons and band practice at the same day 5 times.
Step-by-step explanation:
Hi, to answer this question we have to find the least common multiple (LCM) of both numbers:
5 : 5,10,15,20,25,30,35,40,45,50,55,60,65,70,75,80,85,90,95,100
4: 4,8,12,16,20,24,28,32,36,40,44,48,52,56,60,64,68,72,76,80,84,88,92,96,100
So, the LCM is 20, it means that every 20 days he will have practice and lessons the same day.
If we divide 100 /200 = 5
He will have guitar lessons and band practice at the same day 5 times.
Feel free to ask for more if needed or if you did not understand something.