Quandaries
and Queries
for how many numbers less than 100 is the digit in the ones place half the digit in the tens place?
Hi Paul,
If xy is such a number then y is half of x, so x must be even. How many even digits are there? Once you know x how many choices are there for y?
Once you think you know how many there are, there are only a few, write them all down just to check.
Penny