Two mathematical problems, mathematical experts to solve ah! Satisfaction after the distribution! 1. A and B start at the same point and run in the same direction on the 400 meter circular track. A runs 4 meters per second and B runs 6 meters per second. How long has it been since they started to meet for the first time? 2. There are 25 questions in a test paper. If you do one right, you will get 4 points. If you do wrong or do not answer, you will get 1 point. If a student gets 90 points, how many questions did he do right? The first problem is best solved by equation, fully explain the reason! I will add points! Thank you! It's urgent```````````````

1. Set X seconds after the two meet
6X-4X=400
2X=400
X=200
A: meet in 200 seconds
2. Solve problem X
4X-(25-X)=90
5X-25=90
5X=115
X=23
I answered 23 questions correctly

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