Convert 432,000sec=....days ....hours Find the next two numbers in the following sequence 3; 9; 27; 81; ....... Use the divisibility test method to check if 23,760 is divisible by 11. Solve 4x − 8 = 10x − 20

There are 3600 seconds in 1 hour ($60 \text{ seconds/minute} \times 60 \text{ minutes/hour}$).

There are 24 hours in 1 day.

Since 120 hours is exactly 5 days, there are no remaining hours.

The conversion is $\boxed{\text{5 days 0 hours}}$.

5) Find the next two numbers in the following sequence: 3; 9; 27; 81; ......

Observe the relationship between consecutive terms:
$3 \times 3 = 9$
$9 \times 3 = 27$
$27 \times 3 = 81$
The sequence is a geometric progression where each term is multiplied by 3 to get the next term.

The last given term is 81.
Next number: $81 \times 3 = 243$
Second next number: $243 \times 3 = 729$

The next two numbers are $\boxed{\text{243, 729}}$.

6) Use the divisibility test method to check if 23,760 is divisible by 11.

The rule states that a number is divisible by 11 if the alternating sum of its digits (starting from the rightmost digit) is 0 or a multiple of 11.
For the number 23,760:

Since the alternating sum is 0, the number 23,760 is divisible by 11.

The number 23,760 is $\boxed{\text{divisible by 11}}$.

7) Solve $4x - 8 = 10x - 20$

Subtract $4x$ from both sides:

Add 20 to both sides:

Divide both sides by 6:

The solution is $\boxed{x = 2}$.