=SUMIF(A:A,23,B:B)

If these are valid time entries custom format the result cell to [h]:mm

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---------------
Jacob Skaria


"Yoli" wrote:

How do you state this as a formula? If A4:A8 is the number 23, then add only
the hours in B4:B8 that go with 23.

A B
23 1.5
15 1.0
17 1.0
12 .5
23 .75