On which one do you need help with?
Multiply the number in the tens place of the bottom
number by the number in ones place of the top number. So
multiply the 1 by the 5, which makes 5. Multiply the number in
the tens place of the bottom number by the number in tens
place of the top number. Multiply 1 by 2, which equals 2.
Use this link i cant put it
We know P = 1/2
X~B(2, 0.5)
n = 1
2C1 from pascal triangle = 2
P(X=0.5)= 2C1 x 0.5 x 0.5
= 0.5
= 50%