Prove that the sum of ab and ba is divisible by the sum of a and b
1 answer:
Answer:
It is divisible by 11 and (a + b) !
Step-by-step explanation:
Given a two digit number , the digits written in reverse order is
.
Note that a two digit number ab = 10a + b.
For example: 24 = 10(2) + 4
Similarly, ba = 10(b) + a
Now, the sum of the numbers ab and ba = 10a + b + 10b + a
= 11a + 11b
= 11(a + b)
Hence, the sum of any two digit number ab and the reverse of the number ba, is divisible by 11 and (a + b).
Hence, proved.
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Answer:
B
Step-by-step explanation:
So, to figure this out, we must find the total miles Maria ran in a week.
We know that she ran 2.75 miles each day.
She did this for 7 days.
Her goal was 17.5 miles.
So first, multiply the amount of days by the amount of miles per day:
7*2.75
=
19.25
So now we know that she ran a total of 19.25 miles in a week.
Since she onlu needed to run 17.5 miles, we can instantly rule out:
A - Runs less 17.5 miles
C - Runs exactly 17.5 miles
This leaves:
B - She runs 1.75 miles more than 17.5 miles
D - She runs 2.75 miles more than 17.5 miles
To figure out which on is correct, subtract her total miles by her goal:
19.25-17.5
=
1.75
So we know it must be:
B - She runs 1.75 miles more than 17.5 miles
This is because we figured out she ran an extra 1.75 miles.
Hope this helps! :)
