+425 A number when divided by 10, has a remainder of 7. Another number, when divided by 10, has a remainder of 5. The sum of these numbers is multiplied by 9 to get the final number. What is the remainder of the final number when divided by 10? Give a reason for your answer.
You add the remainder of 7 +5=12 . No matter what 2 numbers you choose, the number will always end in 2. And when you multiply this by 9, the number will always end up in 8. Hence the reainder will always be 8.
Eamaple: 17/10=remainder is 7. 15/10=remainder is 5. Whether you add the numbers we chose:17+15=32 or their reainders: 7+5=12.
+2498 i think:
x is a multiple of 10
\(a=x+7 \\ b=x+5 \\ (a+b)\times9=(2x+12)\times9\\ \frac{18x+108}{10}=\frac{(18x+100)+8}{10} \)
so the remainder is always 8
+128475 Let's call the first number, A .... and it can be represented as 10m + 7
And the second number can be B.......and it can be represented as 10n + 5
So...the sum of these numbers = 10m + 10 n + 7 + 5 = 10m + 10n + 12 = 10(m +n) + 10 + 2 = 10(m + n + 1) + 2
And 9 times this = 90(m + n + 1) + 18 = 90(m + n + 1) + 10 + 8
And dividing this number by 10 is equivalent to dividing each separate term by 10 =
9(m + n + 1) + 1 + 8/10
q + 8/10
The sum of the first two terms produce some integer, q, so.......the remainder is 8.....and Solveit is correct !!!!!
