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.
5 liters (L) of 30% bleach solution contains 0.3×(5 L) = 1.5 L of bleach.
3 L of 50% bleach contains 0.5×(3 L) = 1.5 L of bleach, too.
Combined, you would have 8 L of solution containing 1.5 L + 1.5 L = 3 L of bleach, so the concentration of bleach is
(3 L) / (8 L) = 0.375 = 37.5%
Answer:
C
Step-by-step explanation:
702divded by 6=117
hes taking away