## Explanation

This formula uses two named ranges, "range1" (B5:B12) and "range2" (D5:D10).

The core of this formula is the COUNTIF function, which returns a count of each value in both range inside the AND function:

```
COUNTIF(range1,B5) // count in range1
COUNTIF(range2,B5) // count in range2
```

COUNTIF will either return zero (evaluated as FALSE) or a positive number (evaluated as TRUE) for each value in both ranges.

If both counts are positive (i.e. non-zero), the AND function will return TRUE and trigger the conditional format.

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### COUNTIF Function

The Excel COUNTIF function returns the count of cells in a range that meet a single condition. The generic syntax is COUNTIF(range, criteria), where "range" contains the cells to count, and "criteria" is a condition that must be true for a cell to be counted. COUNTIF can be used to count cells...

### AND Function

The Excel AND function is a logical function used to test multiple conditions at the same time. AND returns TRUE *only if all the conditions are met*. If any conditions are not met, the AND function returns FALSE. The AND function is commonly used with other...