Hi,
The two numbers should be 12 and 30. 12=2x2x3 while 30=2x3x5.
Their HCF is 2x3=6 and their LCM is 2x3x2x5. Because of their HFC, we know that they are both multiple of 6. Also, the question says they both are GREATER than 6, so they can’t be 6 but are 6 times “something”. Thanks to the LCM, we know that “something” is equal to 2 for the first number and to 5 for the second one, the numbers hence being 12 and 30.
I hope this helps. If I was not clear enough or if you’d like further explanation please let me know. Also, English is not my first language, so I’m sorry for any mistakes.
Answer:

Step-by-step explanation:
The error in rounding a number is half of the unit of measure.
The number was rounded to the nearest 0.1 unit so the error is 1/2×0.1, which equals 0.05.
Now we add 3.7 and 0.05, which equals 3.75 and we also take 3.7 - 0.05, which equals 3.65
So, the error interval is:

There would be 100,000 if there are no restrictions on the digits and 90,000 if they cannot use 0 as the first digit.
If there are no restrictions, there are 10 possibilities for each digit:
10(10)(10)(10)(10) = 100,000
If the first digit cannot be 0, there are 9 possibilities for it and 10 possibilities for each of the other 4:
9(10)(10)(10)(10) = 90,000
The simple way of calculating a perimeter is to add all of the sides.
For a rectangle this would equal 2 x length + 2 x width
P = 2(6x + 3) + 2(-2x - 5)
= 12x + 6 - 4x - 10
= 8x - 4
At a higher level both the length and width must be greater than zero (= zero is a trivial rectangle)
6x + 3 > 0
6x > -3
x > -0.5
-2x - 5 > 0
2x + 5 < 0 (multiplying by -1 reverses the inequality)
2x < -5
x < -2.5
This rectangle cannot exist as x cannot be < -2.5 and > -0.5 at the same time!