Answer:
The diameter is 14
Step-by-step explanation:
The area of a circle is given by
A = pi r^2
We know the area is 49 pi
49 pi = pi r^2
Divide each side by pi
49 pi/ pi = pi r^2/pi
49 = r^2
Take the square root of each side
sqrt(49) = sqrt(r^2)
7 =r
We want the diameter
d = 2r
d = 2*7
d = 14
Answer:
i don't know
Step-by-step explanation:
The cost of each duck is $ 7 and cost of each chicken is $ 12.
Step-by-step explanation:
Given,
5 chickens and 3 ducks are bought by $ 81
A chicken costs $ 5 more than a duck.
To find the cost of each duck and cost of each chicken.
Let,
The cost of each duck = x
The cost of each chicken = x+5
According to the problem,
5(x+5)+3x = 81
or, 5x+25+3x = 81
or, 8x = 81-25
or, 8x = 56
or, x = 7
Hence,
The cost of each duck = $ 7
The cost of each chicken = $ 7+5 = $ 12
