Ten runners joine a race .in how many possible ways can they be arranged as first devond and third placers?

Jenisey has $24 to spend on seven pencils. after buying them she had $10. how much did each pencil cost.?

You're locked out of your house. the only open window is on the second floor, 25 feet above the ground. there are bushes along the edge of the house, so you will need to place the ladder 10 feet from the house. what length ladder do you need to reach the window?

The ratio of the perimeters of two similar triangles is 4: 3. what are the areas of these triangles if the sum of their areas is 130cm2?