The key is to set up two variables and write two equations — this is a classic simultaneous equations Problem Solving question, and the trap is getting tangled in the words before you even set up anything.
Let m = workers late on morning shift Monday, a = workers late on afternoon shift Monday. So T = m + a.
1. Tuesday condition: twice as many on morning, 1/3 as many on afternoon, total = 36.
That gives us: 2m + a/3 = 36. Multiply everything by 3: 6m + a = 108.
2. Wednesday condition: three times as many on morning, 9 fewer on afternoon, total = 54.
That gives us: 3m + (a - 9) = 54, which simplifies to: 3m + a = 63.
Now subtract equation 2 from equation 1:
(6m + a) - (3m + a) = 108 - 63
3m = 45
m = 15
Plug back into 3m + a = 63: 45 + a = 63, so a = 18.
T = 15 + 18 = 33.
Morning workers on Monday as a fraction of T: 15/33 = 5/11. So m = 5T/11.
Answer: B.
The trap most people fall into is setting up the Wednesday equation wrong — the problem says "9 fewer workers late on the afternoon shift than on Monday afternoon," so it's (a - 9), not (a + 9). Flip that sign and you'll get a totally different answer that looks plausible. Worth double-checking that condition before moving on.