Answer:
Correct answer is
Step-by-step explanation:
As per the given diagram, we know the following details:
Height of the triangular pyramid is <em>14m</em>.
<em>Side of base</em> = <em>10m
</em>
Height of Triangular base = <em>8.7m</em>
Formula for <em>surface area of triangular pyramid</em>:

(Triangular base is shown in the dotted lines in the question figure.
The other 3 triangles are the side triangles.)
We know that,


Hence correct answer is
.
Half (or 26) of the cards are red, and the rest are black.
P(randomly selected card is red) = 26/52 = 1/2.