We know that
if <span>4 electricians can complete a job in 8 hours
then
</span>100% of a job -------> 8 hours
x------------------> 1 hour
x=100/8----> x=12.5%
divide by 4 electricians
12.5%/4-----> 3.125%
that means each electrician can complete 3.125% of a job in 1 hour
therefore
3 electricians-----> 3*3.125%----> 9.375% in 1 hour
so
9.375%-----------> 1 hour
100%--------------> x
x=100/9.375----> x=10.67 hours
the answer is
10.67 hours
2/3, 5/6, 4/7....common denominator is 42
2/3 = 28/42
5/6 = 35/42
4/7 = 24/42
least to greatest : 2/3, 5/6, 4/7
3/4, 7/12, 4/5....common denominator is 60
3/4 = 45/60
7/12 = 35/60
4/5 = 48/60
least to greatest : 7/12, 3/4, 4/5
7/10, 8/15, 11/20.....common denominator is 60
7/10 = 42/60
8/15 = 32/60
11/20 = 33/60
least to greatest : 8/15, 11/20, 7/10
Multiples of 8 through 60 are 8, 16, 24, 32, 40, 48 and 56
No. of favorable outcomes= 7
Thus, P(E)=7/60
ANSWER

EXPLANATION
From the table the values of x, are on the left and the values of f(x) are on the right.
To find f(-1), we look for the value under f(x) that corresponds to x=-1.
This value is 0.
Therefore
