Answer:
D) 25.5 cm
Step-by-step explanation:
Circumference = pi × d
20 = 3.14 × d
d = 6.3694267516
Diameter = length of one side
Perimeter of the square = 4s
4(6.3694267516)
25.4777070064 cm
From the options, closest is 25.5
Answer:
25 doughnuts
Step-by-step explanation:
for 15 workers,
the numbers of doughnuts =
5 doughnuts/3 workers × 15 workers
= 75/3 doughnuts
= 25 doughnuts
Let
be the speed of train A, and let's set the origin in the initial position of train A. The equations of motion are

where
are the positions of trains A and B respectively, and t is the time in hours.
The two trains meet if and only if
, and we know that this happens after two hours, i.e. at 

Solving this equation for v we have

So, train A is travelling at 105 km/h. This implies that train B travels at

Answer:
C
Step-by-step explanation:
There can be multiple solutions when two lines intersect.