Searching for "patterns" in Excel

Hello! I'm sorry but I couldn't find my answer in the search box.

I am new to Excel but I want to learn more so that I can give our auditors and analysts a well deserved break. Plus I can get what I need quicker since they are often busy

I am analyzing a spreadsheet that shows a person's trips (I removed and altered the data in the attached spreadsheet). I just finished reviewing a spreadsheet to see if it had any possible mistakes due to this spreadsheet's total $ amount being different from other records. The spreadsheet had over 900 rows and I looked over each of them manually to see if I could notice any mistakes. I found 3 possible problem areas (which I highlighted). I do not know if the data was inputted incorrectly or if the other records are wrong. But I am hoping to verify everything that I can. In order to be more efficient I was wondering if there is a way to search for patterns in an excel spreasheet?
Specifically for this case I want to see if one row is related to the one above. For this spreadsheet I wanted to make sure that the Trip Dates column each had a matching pair (so if there was a 04/08/18 there should be a 04/08/18 in the row below it). I also wanted to see if the Trip ID column had a corresponding ****-A and ****-B (**** being the same) in the row below it. I spent a lot of time doing this manually but I was hoping that there was a way to automate it?

Thank you for your time!

FDibbins/SHG,

Thank you both for your responses! I wanted to reply to you both before I looked utlized what you both answered (since I know its going to take some time for me to understand it lol).

FDibbins - there should only be two for trips for each corresponding date. But there might be multiple trips (two parts) on the same date. But there is one instance in which there are 3 trips for that corresponding date (i think this is a mistake since everything else is just two parts.

I apologize if it's a little confusing lol..... Basically a person is driving themself from their home to another location. That person should only have those two trips and they get reimbursed for the drive from their home to that location and the drive from that location home. Those two trips take place on that same date.

*I apologize but I didn't know that I couldn't give you both reputation for your help : /

Originally Posted by shg

This check for matching A/B pairs:

	A	B	C	D	E
1	Trip Date	Trip Id	Status
258	02/11/2016	01-120734-C	Verified-Paid	FALSE	D258: =COUNTIF(B257:B259, LEFT(B258, LEN(B258) - 1) & IF(RIGHT(B258) = "A", "B", IF(RIGHT(B258)="B","A"))) = 1
337	05/31/2016	01-116719-C	Verified-Paid	FALSE
370	06/29/2016	01-106939-A	Verified-Paid	FALSE
371	06/29/2016	01-106939-C	Verified-Paid	FALSE
644	06/08/2017	01-102583-C	Verified-Paid	FALSE
803	11/27/2017	01-117241-A	Verified-Paid	FALSE
804	11/28/2017	01-108828-A	Verified-Paid	FALSE

Thats it! You found more instances that I didn't even notice! Thank you for your help. I just don't understand how you did it yet lol. I'm trying to look up the formulas right now.