Answer:
10/39
Step-by-step explanation:
The chances of picking a black sock on first try are 8/13, and the chances of picking out a yellow sock without replacing the black sock are 5/12. If you multiply 8/13 and 5/12, you get 40/156, and if you simplify, you will get 10/39 as your answer.
The answer and working are shown in the photo below
Answer:
dC = 2.44
Relative error = 19%
Step-by-step explanation:

Δv = 3 ; ΔT = 1 , v = 23, T = 8
Use differential Calculus


Relative Error
dC / C @(T = 8, v=23) * 100 = 19 %
U = -b + 21 . . . (1)
u = -2b + 30 . . . (2)
Equating (1) and (2),
-b + 21 = -2b + 30
-b + 2b = 30 - 21
b = 9
u = -9 + 21 = 12
Therefore, (b, u) = (9, 12).