F(1) = (1)^2 + 1 = 2
g(4) = 3*4+1 = 13
2f(1) + 3g(4) = 2*2 + 3*13 = 43
Answer: The area of the shaded sectors is 35.3 square kilometres
Step-by-step explanation: What we have here is a circle with center Z. Two sectors have been formed which are ZVW and ZYX. A careful observation reveals that both sectors are similar. If WY passes through the center Z then WY is a diameter. The same applies to VX, since it also passes through the center, therefore it is a diameter. Both lines intersect at the center, that makes both sectors to have the same radii which is 5.3 km and same applies to the angle subtended at the center of the sector, both angles are opposite angles formed by intersecting lines (opposite angles formed by intersecting lines are equal). On a straight line WY, the sum of angles ∠WZX and ∠YZX equals 180 degrees (Sum of angles on a straight line equals 180). Therefore;
WZX + YZX = 180
108 + YZX = 180
Subtract 180 from both sides of the equation
YZX = 72°
Therefore the area of shaded sector YZX is given as;
Area of a sector = (∅/360) x πr²
Where ∅ is 72, and r is 5.3
Area of sector = (72/360) x 3.14 x 5.3²
Area of sector = 0.2 x 3.14 x 28.09
Area of sector = 17.64
Having in mind that both sectors are similar (the same radii and the same central angle), the area of the shaded sectors shall be equal to 17.64 times 2 and that equals 35.28. (That is approximately 35.3 to the nearest tenth)
The area of the shaded sectors therefore is 35.3 square kilometres (35.3 km²)
Time taken by Ella is 0.6 hour
<u>Solution:</u>
Lily finished a task in
hour
Ella finished it in
of time Lily took
<em><u>To find: time taken by Ella to finish the task</u></em>
Let "L" be the time taken by Lily
Time taken by Lily = L = 
From given statement,
Time taken by Ella to finish the task is
of time Lily took
Therefore,
Time taken by Ella =
of time taken by Lily

Thus time taken by Ella is 0.6 hour
This is the concept of trigonometry, we are required to calculate the number of floors the building has given the information above;
# floors=[height of the building]/[height of each floor]
height of each floor=17 ft
let the height of the building be,h.
h is given by;
tan theta=opposite/adjacent
theta=80
opposite=h
adjacent=75 ft
thus
tan 80=h/75
h=75 tan 80
h=425.35 ft
thus the number of floors will be:
425.35/17
=25.020≈25 floors