The probability that the first random choice will be a matho-file and not a -phobe is 18/23. The probability of the second one is 17/22, and for the third one it's 16/21. The probability of all 3 is 4,896/10,626 = (18x17x16)/(23x22x21). That's 46.1% (rounded).
Answer:
7 strips
Step-by-step explanation:
One way we can solve this is through guess and check. Let's start with 4 strips. If Joe's grandma makes 4 strips, she will have 0.75*4 = 3.00 yards of fabric. That's a really low amount of fabric. Let's double that to 8, where Joe's grandma would need 0.75*8 = 6.00 yards of fabric. That's really close! Let's remove one strip. 0.75*7 = 5.25 yards of fabric. Perfect! Joe's grandma can cut exactly 7 strips