50% because it can either girl or boy first. I hope i helped
I would say it’s C because you make X negative
20 = 40e^-0.1446t
e^-0.1446t = 0.5
t = ln 0.5 / -0.1446
t = 4.8 days
B. 15 + 26 ( use order of operations )
AND
D. 20 + 21 ( use the associative property )
