maths

posted by .

Consider a 25×25 grid of city streets. Let S be the points of intersection of the streets, and let P be the set of paths from the bottom left corner to the top right corner of which consist of only walking to the right and up. A point s is chosen uniformly at random from S and then a path p is chosen uniformly at random from P. Over all (s,p) pairs, the probability that the point s is contained in the path p can be expressed as ab where a and b are coprime positive integers. What is the value of a+b?

Details and assumptions
There are 25 streets running in each direction, so S consists of 625 intersections.

• maths -

where did you get this question?

• maths -

It comes from an Olympiad Maths problem

• maths -

• maths -

It does not have a link.
It is on paper.

• Cheaters -

Ok.
These are lame cheaters.

• maths -

SOlved.

• maths -

to ok. if you want to answer this on the site brilliant, you can by making an account but unfortunately, in every account, they have different sets of question basing on the level what you are in. this is such a very easy question.

• maths -

• maths -

Similar Questions

1. Physics

At each corner of a square of side script i there are point charges of magnitude Q, nQ, mQ, and 4Q, where n = 3 and m = 3. Determine the force on the charge mQ due to the other three charges. (mQ is on the bottom right corner, nQ is …
2. algebra

There are two similar triangles. The angles are: from top to bottom left: DE, from bottom left to right: EF, And from Top to bottom right corner: DF. DE: 10.32 cm.EF: 8.88 cm.FD 12.24 cm. The angles are: D,top,45 Degrees. E, bottom …
3. math

Consider a 25×25 grid of city streets. Let S be the points of intersection of the streets, and let P be the set of paths from the bottom left corner to the top right corner of which consist of only walking to the right and up. A point …
4. math

Consider a 25×25 grid of city streets. Let S be the points of intersection of the streets, and let P be the set of paths from the bottom left corner to the top right corner of which consist of only walking to the right and up. A point …
5. maths

A dog is standing at the bottom left corner of a grid of 46×46 streets. The dog is trying to get to the top right corner of the grid, where it knows there is some food. As the dog runs, between the corners, it will only ever run up …
6. math

Consider a 25×25 grid of city streets. Let S be the points of intersection of the streets, and let P be the set of paths from the bottom left corner to the top right corner of which consist of only walking to the right and up. A point …
7. math

Consider a 25×25 grid of city streets. Let S be the points of intersection of the streets, and let P be the set of paths from the bottom left corner to the top right corner of which consist of only walking to the right and up. A point …
8. math

Consider a 25×25 grid of city streets. Let S be the points of intersection of the streets, and let P be the set of paths from the bottom left corner to the top right corner of which consist of only walking to the right and up. A point …
9. maths

Consider a 25×25 grid of city streets. Let S be the points of intersection of the streets, and let P be the set of paths from the bottom left corner to the top right corner of which consist of only walking to the right and up. A point …
10. math

A dog is standing at the bottom left corner of a grid of 46×46 streets. The dog is trying to get to the top right corner of the grid, where it knows there is some food. As the dog runs, between the corners, it will only ever run up …

More Similar Questions