Base of a triangle is 9 and height is 5. Base of another triangle is 10 and height is 6. Find the ratio of areas of these triangles.

Let base of the first triangle is b₁ and height is h₁. Let base of second triangle is b₂ and height is h₂.
Ratio of areas of two triangles is equal to the ratio of the products of their bases and corresponding heights.
Here b₁ = 9
h₁ = 5
b₂ = 10
h₁ = 6
Then ratio of their areas = b₁×h₁/b₂×h₂
= 9×5/10×6
= 3/4
Hence the ratio of the areas of these triangles is 3:4