Step-by-step explanation:
(a+bi)2
=a2 +2abi +b2i2
=a2 +2abi + b2. (-1)
=a2 -b2 +2abi
Answer = (a+b(a-b) +2abi
Number of students = 26
Number of students without siblings = 4
⇒ Number of students with at least one siblings = 26 - 4 = 22
Number of students with brothers = 17
Number of students with sisters = 7
⇒ Number of students with both a brother and a sister = 17 + 7 - 22 = 2
P(student has a brother, given that they have a sister) = 2/7
Answer: 2/7
Answer:
Step-by-step explanation:
