Question

What is the probability that a random counter falls on trapezoid

Answer 1

The probability that the counter falls inside the trapezoid can be calculated by comparing the area of the trapezoid and the total area.

The area of a trapezoid of bases b1 and b2, and height h is:

`A_t=(b_1+b_2)/(2)\cdot h`

The longer base measures b1 = 7 and the shorter base measures b2 = 3. The height is the horizontal distance between the bases, thus h = 6.

Substituting:

`\begin{gathered} A_t=(7+3)/(2)\cdot6 \\ A_t=30 \end{gathered}`

The total area of the grid is 10 × 10 = 100.

The required probability is:

`p=(30)/(100)=(3)/(10)=0.3`

The probability is 3/10 or 0.3 or 30%