Answer:
20 mens are needed to contruct a building in 32 days.
Answer with explanation:
Let us assume that the 2 functions are:
1) f(x)
2) g(x)
Now by definition of concave function we have the first derivative of the function should be strictly decreasing thus for the above 2 function we conclude that

Now the sum of the 2 functions is shown below

Diffrentiating both sides with respect to 'x' we get

Since each term in the right of the above equation is negative thus we conclude that their sum is also negative thus

Thus the sum of the 2 functions is also a concave function.
Part 2)
The product of the 2 functions is shown below

Diffrentiating both sides with respect to 'x' we get

Now we can see the sign of the terms on the right hand side depend on the signs of the function's themselves hence we remain inconclusive about the sign of the product as a whole. Thus the product can be concave or convex.
Answer:
Step-by-step explanation:
If two chords intersect inside a circle, then
DE * BE =AE * CE
10*x = 8*6
10x = 48
x = 48/10
x = 4.8
Answer:
Mean = 75
Median = 73.5
Mode = 95
Range = 36
Step-by-step explanation:
Given:
Sort:
To find:
Mean:

Sum of all data divides by amount.

Therefore, mean = 75
Median:
If it’s exact middle then that’s the median. However, if two data or values happen to be in <em>middle</em>:

From 59,60,70,77,89,95, since 70 and 77 are in middle:

Therefore, median = 73.5
Mode:
The highest value or/and the highest amount of data. Mode can have more than one.
From sorted data, there are no repetitive data nor same data. Consider the highest value:
Therefore, mode = 95
Range:
or highest value - lowest value
Thus:

Therefore, range = 36
Answer:
The volume of a cone is:
V=(hπr^2)/3, where h=height and r=radius
V=(7π4^2)/3
V=112π/3 ft^3
V≈117.29 ft^3 (to nearest hundredth of a cubic foot)
Step-by-step explanation: