This is the concept of arithmetic. To calculate the percentage of time life has existed we proceed as follows;
According to history:
The age of earth is 4.6 billion years
the age of life is as it appeared from unicellular is 3.8 billion years.
thus the percentage of the above will be:
3.8/4.6 x 100
=0.82609x100
=82.609%
Answer: 54
Step-by-step explanation:
Answer:
Part A:
(1) x + y = 95
(2) x = y + 25
Part B:
The number of minutes Eric spends playing volleyball each day is 35 minutes
Part C:
It is not possible for Eric to have spent exactly 35 minutes playing basketball
Step-by-step explanation:
The total time Eric plays basketball and volleyball = 95 minutes
The time duration Eric plays basket ball = x
The time duration Eric plays volleyball = y
Part A:
The pair of relationships between the number of minutes Eric plays basketball (x) and the number of minutes he plays volleyball (y) are;
(1) x + y = 95
(2) x = y + 25
Part B:
By substituting the value of x in equation (2) into equation (1), we have;
x + y = (y + 25) + y = 95
2·y + 25 = 95
2·y = 95 - 25 = 70
y = 70/2 = 35 minutes
Therefore, Eric spends 35 minutes playing volleyball every day
Part C:
It is not possible for Eric to have spent only 35 minutes playing basketball because, given that he plays basketball for 25 minutes longer than he plays volley, the number of minutes he spends playing volleyball will then be given as follows;
x = y + 25
35 = y + 25
y = 35 - 25 = 10 minutes
The total time = x + y = 10 + 35 = 45 minutes ≠ 95 minutes.
Answer:
-1, 2
Step-by-step explanation:
X/4-9=5
x/4=14
x=14/4
x=7/2
x=3.5