Answer:
a = 14
Step-by-step explanation:
The mean is the sum of the values divided by the number of values.

<span>3.60555128 is the awnser</span>
He wrote the number 1892, because:
The number needs to be less than 2000, with four digits. Because the first is half the last, it means that the number must be 1??2.
These two numbers add up to 3, and all together, they need to add to 20. 20-3=17. The remaining numbers need to add to 17.
The only two single digit numbers that can add to 17, are 8 and 9. Therefore, the number must either be 1892 or 1982.
The second digit needs to be even, meaning that the number has to be 1892.
I hope this helps.
Answer:
1089
Step-by-step explanation:
The original number is A0CD, We have that DC0A = 9 x A0CD.
If A =1, then D = 9 and we have:
9C01 = 9 x 10C9
In order for this expression to be true, the following must also be true:
(C x 9) + 8 must be divisible by 10, which means that C x 9 must end in a 2.
The only multiple of 9 (from 9 to 81) that ends in a 2 is 72.
72 = 9 x 8.
Therefore, C must be 8 and the original number is 1089. Multiply it by 9 to check the answer:
1089 x 9 = 9,081
Therefore, 1089 is correct.
13/8 or 1 5/8
3/4 becomes 7/8 when add it is 13/8