Question

Write an expression that, given a positive integer n, computes a new integer in which the units and tens digits have swapped places.

A. n+90

B. 10n+n/10
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C.10n+n%10/10
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D.10(n%10)+n/10
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Answer 1

The correct expression to swap the units and tens digits of a positive integer n is: 10(n%10) + n/10.

Step-by-step explanation:

The correct expression to swap the units and tens digits of a positive integer n is: 10(n%10) + n/10.

Let's break down the expression step by step:

1. n%10 is used to get the remainder when n is divided by 10. This gives us the units digit of n.
2. 10(n%10) multiplies the units digit by 10 to make it the new tens digit.
3. n/10 is used to get rid of the original tens digit. It performs integer division to remove the units digit.
4. Finally, 10(n%10) + n/10 adds the new tens digit (10(n%10)) and the removed units digit (n/10) to form the new integer.