Answer:
its D
Step-by-step explanation:
the third choice, (3x4) + (3x5) = 27
Let, x be the maximum hours he can rent skate board and helmet.
So, total price :
T = 4x + 6x
Now, it is given that he has only $30.
Therefore,
Total price should be less than or equal to $30.
4x + 6x ≤ 30
10x ≤ 30
x ≤ 3
Therefore, the maximum number of hours he can rent the skateboard is 3 hours.
Hence, this is the required solution.
If 2x+y=5, then y=5-2x, so he substituted 5-2x correctly.
x+4x=5x, so he combined like terms correctly.
If 5x-10=10, then 5x=10+10 -> 5x=20, so he subtracted 10 from the right side instead of adding 10 to the right side.
The answer is C.
Here's the correct solution:
Answer:
The relative growth rate is 18.75%.
Step-by-step explanation:
If the world population was 2.560 million in 1950 and 3.040 million in 1960, it means that there was a growth of 480 million people in 10 years. Thus, it is a growth of 18.75%, according to the following calculation:
2,560 = 100
480 = X
(480 x 100) / 2,560 = X
48,000 / 2,560 = X
18.75 = X
Therefore, if this growth rate were to be maintained, in subsequent years the world population would evolve as follows:
1970: 3,040 x 1.1875 = 3,610 million inhabitants
1980: 3,610 x 1.1875 = 4,286 million inhabitants
1990: 4,286.8 x 1.1875 = 5,090 million inhabitants
