The answer to your Question is 8/10 but if you simplify it the answer is 4/5.
The relative frequency of selecting a diamond from 40 trials of selecting a random card is 30%.
<h3>What is relative frequency?</h3>
The relative frequency of an event is the ratio of total number of favorable or desired outcome to the total number of trails done.
Given information-
The card is selected random from the deck of cards.
Total number of trails is 40.
It is known that the total number of diamond card in a standard deck of card is 11. There is total 40 trials is done in which a random card is selected.
As the relative frequency is the ratio of total number of diamonds to the total number of trials done. Thus,

In the percentage from,

Thus the relative frequency of selecting a diamond from 40 trials of selecting a random card is 30%.
Learn more about the relative frequency here;
brainly.com/question/26177128
2(5*10)+2(10*4)+2(5*4)=
2(50)+2(40)+2(20)=100+80+40=
220 cm^2
I found the answer by finding the areas of the 3 different sides, multiplying each area by 2 since each side has another side that is equal on a rectangular prism, then adding all of them together.
250 cm because area equals LxW and 25x10=250
A line would be best used to model the surface of an aquarium, by putting a line on top of the surface and checking if the water is level or not.