The image contains a math problem written in Korean. Let me translate and solve it step by step.
The problem says:
"Find the number of integers between 1 and 100 (inclusive) that are divisible by 3 or 5."
Let me solve this:
Step 1: Count numbers divisible by 3 between 1 and 100
- These are: 3, 6, 9, 12, ..., 99
- This is an arithmetic sequence where the first term is 3 and the last term is 99
- Number of terms = 99 ÷ 3 = 33
Step 2: Count numbers divisible by 5 between 1 and 100
- These are: 5, 10, 15, 20, ..., 100
- This is an arithmetic sequence where the first term is 5 and the last term is 100
- Number of terms = 100 ÷ 5 = 20
Step 3: Count numbers divisible by both 3 and 5 (i.e., divisible by 15)
- These are: 15, 30, 45, 60, 75, 90
- Number of terms = 90 ÷ 15 = 6
Step 4: Use the inclusion-exclusion principle
- Total = (divisible by 3) + (divisible by 5) - (divisible by both)
- Total = 33 + 20 - 6 = 47
Let me verify:
- Numbers divisible by 3: 33 numbers
- Numbers divisible by 5: 20 numbers
- Numbers divisible by both (15): 6 numbers
- Using inclusion-exclusion: 33 + 20 - 6 = 47
This is correct.
Final Answer: 47
Parent Tip: Review the logic above to help your child master the concept of blank recipe card template word.
