The question does not seem complete, but I'll represent the statement mathematically and look for their ages each. This is because the worst they can ask for is their ages.
Let C stand for Courtney's age, A for Andrei's age, N for Natalie's age and S for Shari's age. From the question we can deduce the following:
C = 2A
C = N + 3
C = S/2
S - N = C + A
S = 2C, N = C - 3 and A = C/2, therefore we have
2C - (C - 3) = C + C/2
C + 3 = C + C/2
C/2 = 3 and C = 6
A = C/2
A= 6/2
A = 3
N = C - 3
N = 6 - 3
N = 3
S = 2C
S = 2 x 6
S = 12.
C = 6, A = 3, N = 3 and S = 12
Answer:
option A. 21 sec
Step-by-step explanation:
Speed = the distance over the time
Given:
Speed = 2 m/s and distance = 42 m and time = t
So,
2 = 42/t
Solve for t
t = 42/2 = 21 sec.
The answer is option A. 21 sec
Answer:

Step-by-step explanation:
step 1
Find the volume of the tank

step 2
we know that
If the tank is 1/3 full of water
then
the volume of water required to completely fill the tank is equal to 2/3 of the tank capacity
so

Answer:
n-58
Step-by-step explanation:
Answer: Option D.
Step-by-step explanation:
A figure has a line of symmetry if we can draw a line through the figure, in such way that the line cuts the figure in exactly two equal halves.
Then any figure that can be cutin exactly two halves, is a correct answer to this question.
Then:
For a circle, the line of symmetry is the diameter of the circle.
For the square, the line of symmetry can be obtained by cutting the square with a line that is perpendicular to one of the sides, and cuts that side exactly on the midpoint.
For an equilateral triangle, the line of symmetry is the line that cuts any base in the midpoint and also passes through the opposite vertex.
Then all the figures are correct options, then the correct option is D