For each 100 8th grade girls in a certain middle school, 85 play soccer, 70 have a cell phone, 75 have a tablet computer, and 80 play a musical instrument. What is the least possible number of these 100 girls who play soccer, have a cell phone, own a tablet computer, and play a musical instrument?
To find the least possible number of girls who play soccer, have a cell phone, own a tablet computer, and play a musical instrument, we need to determine the maximum number of girls who do not have all of these four attributes.
Step 1: Find the maximum number of girls who do not play soccer.
To find this, subtract the number of girls who play soccer (85) from the total number of girls (100):
100 - 85 = 15
Step 2: Find the maximum number of girls who do not have a cell phone.
Using the same logic, subtract the number of girls who have a cell phone (70) from the total number of girls (100):
100 - 70 = 30
Step 3: Find the maximum number of girls who do not own a tablet computer.
Following the same pattern, subtract the number of girls who own a tablet computer (75) from the total number of girls (100):
100 - 75 = 25
Step 4: Find the maximum number of girls who do not play a musical instrument.
Subtract the number of girls who play a musical instrument (80) from the total number of girls (100):
100 - 80 = 20
Step 5: Determine the least possible number of girls who have all four attributes.
To find this, find the maximum number of girls who do not have all four attributes:
15 (from Step 1) + 30 (from Step 2) + 25 (from Step 3) + 20 (from Step 4) = 90
Finally, subtract this maximum number from the total number of girls:
100 - 90 = 10
Therefore, the least possible number of these 100 girls who play soccer, have a cell phone, own a tablet computer, and play a musical instrument is 10.