Solve multiplication problems to reveal the hidden message.

To solve this puzzle, we need to match each number in the message lines with the correct letter from the key at the top. The key gives us a multiplication problem for each letter. We will solve those problems first to know which letter matches which number.

Step 1: Solve the Key

Let's calculate the value for each letter:

* A: $11 \times 11 = 121$
* C: $3 \times 50 = 150$
* D: $20 \times 5 = 100$
* G: $4 \times 60 = 240$
* H: $10 \times 40 = 400$
* L: $8 \times 9 = 72$
* Y: $6 \times 90 = 540$
* N: $9 \times 7 = 63$
* O: $8 \times 6 = 48$
* P: $60 \times 2 = 120$
* I: $76 \times 10 = 760$
* S: $15 \times 2 = 30$
* W: $7 \times 6 = 42$
* U: $9 \times 12 = 108$

Now we have our code:
* 121 = A
* 150 = C
* 100 = D
* 240 = G
* 400 = H
* 72 = L
* 540 = Y
* 63 = N
* 48 = O
* 120 = P
* 760 = I
* 30 = S
* 42 = W
* 108 = U

Step 2: Decode the Message

Now let's look at the rows of numbers and replace them with letters using our code.

Row 1: `42 760 30 400 760 63 240` ... `540 48 108`
* 42 → W
* 760 → I
* 30 → S
* 400 → H
* 760 → I
* 63 → N
* 240 → G
* *(space)*
* 540 → Y
* 48 → O
* 108 → U
* Word: WISHING YOU

Row 2: `121` ... `400 121 120 120 540`
* 121 → A
* *(space)*
* 400 → H
* 121 → A
* 120 → P
* 120 → P
* 540 → Y
* Word: A HAPPY

Row 3: `30 150 400 48 48 72`
* 30 → S
* 150 → C
* 400 → H
* 48 → O
* 48 → O
* 72 → L
* Word: SCHOOL

Row 4: `400 48 72 760 100 121 540`
* 400 → H
* 48 → O
* 72 → L
* 760 → I
* 100 → D
* 121 → A
* 540 → Y
* Word: HOLIDAY

Step 3: Put it all together

The full message is:
WISHING YOU A HAPPY SCHOOL HOLIDAY

Final Answer:
WISHING YOU A HAPPY SCHOOL HOLIDAY