Answer:
The LCM of 3 and 7 is 21.
Step-by-step explanation:
Answer:
a = 1/6
Step-by-step explanation:
To solve, divide both sides by 5 1/4
a = 7/8 / (5 1/4)
a = (7/8) / (21/4)
a= 7/8 * 4/21
a= 28/168
a= 1/6
Step-by-step explanation:
look at the picture !
she has to paint actually 6 rectangles :
the 3 tops of the 3 stairs.
and the 3 vertical front boards (the front of each step of the stairs).
what is the area of these rectangles ? summing up all 6 - that is the surface area to be painted.
each top rectangle is clearly
82×19 (19 cm deep) = 1558 cm²
each front board is
82×12 (12 cm high) = 984 cm²
so, in total we have
3×1558 + 3×984 = 4674 + 2952 = 7626 cm²
as surface area to be painted.
V=hpir^2
h=20
r=12
v=20pi12^2
v=20pi144
v=2880pi
2nd one is answer
