Answer:
18
Step-by-step explanation:
Answer:
X
Step-by-step explanation:
Answer:
7 hours 30min
Step-by-step explanation:
Step one :
Given data
We are told that Erica can paint 1 room in 5hours
Her work rate is 1/5 room per hour
And also with the assistance of her friend they can paint 1 room in 3 hours
Hence their combined work rate is 1/3 room per hour
Step two
The combined work expression is
1/A+1/B=1/T
Where A=Erica's work rate
B=Rachael's work rate
T=combined work
1/5+1/B=1/3
1/B=1/3-1/5
1/B=5-3/15
1/B=2/15
B=15/2
B=7.5 hours
It will take Rachel 7 hours 30min to paint the room
Answer:
60°
Step-by-step explanation:
ABCO is a parallelogram (opposite sides are parallel).
AO is equal to the radius of the circle, so BC must also equal the radius.
CO is equal to the radius of the circle, so AB must also equal the radius.
If we draw a line from O to B, we split the parallelogram into two triangles. Since OB is equal to the radius of the circle, each triangle is an equilateral triangle. Therefore, angle A is 60°.