Math
posted by Anonymous on .
How would you work this problem?
The odometer of the family car read 15951 when the driver noticed that the number was palindromic. "Curious," said the driver. "It will be a long time before that happens again." But two hours later, the odometer showed a new palindromic number. How fast was the car traveling in those two hours?

A palindromic number or word reads the same forward and backward.
Cars travel an average of 40 to 70 miles per hour. In two hours the car probably traveled between 80 and 140 miles.
Which digits can you change in 15951 to give a palindrome representing 80 to 140 miles?
What is that in mph?
If you post your answer, we'll be glad to check it. 
Would the answer be 50 mph?
25952  15952=10000 divided by 2 hours? 
I already told you that the car probably traveled between 80 and 140 miles in two hours. That's a long way from 10,000 miles!!!
Hint: the second digit must be 6. 
16961
1696115951=1010/2=51 mph? 
I have no clue!

25952?

You have to consider that 25952 is not reasonable. A car could not travel 5,000 miles in 1 hr (10000/2). Not even a jet engine could travel that fast.
Why not try using EXCEL to create a table at various speeds and observe what you come up with. 
1696115951=1000/2=51 mph?

Nope. 1000/2 = 50

1000/2 does not = 50.

How about 16061?

Ok...thanks!

110

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The next palindromic number would be
16061 so subtract 15951 from that then divide by the 2 hours
1606115951=110
110/2X X=55