Answer:
b. Steve's Scratch and Dent.
Step-by-step explanation:
Tom should purchase his washing machine from Steve's Scratch and Dent.
Let 
be the random variable for the number of marks a given student receives on the exam.
10% of students obtain more than 75 marks, so
where 
follows a standard normal distribution. The critical value for an upper-tail probability of 10% is
where 
denotes the CDF of , and 
denotes the inverse CDF. We have
Similarly, because 20% of students obtain less than 40 marks, we have
so that
Then 
are such that
and we find
Answer:
Hulian's age is 7.
Thomas's age is 22.
Step-by-step explanation:
Let Hulian = h
Let Thomas = t
Set the system of equation:
h = t - 15
h + t = 29
Plug in t - 15 for h in the second equation:
(t - 15) + t = 29
Simplify. Combine like terms:
2t - 15 = 29
Isolate the variable, t. Note the equal sign, what you do to one side, you do to the other. Do the opposite of PEMDAS. First, add 15 to both sides:
2t - 15 (+15) = 29 (+15)
2t = 44
Divide 2 from both sides:
(2t)/2 = (44)2
t = 44/2
t = 22
Plug in 22 for t in one of the equations:
h = t - 15
h = 22 - 15
h = 7
Hulian's age is 7.
Thomas's age is 22.
~
This is an EXPONENT.
To do this all we need to do is multiply the base by itself how many times the power says.
(-6)² = (-6) × (-6) = 36
Recall that any negative number times another negative number is positive so that is why this would be positive.
So, (-6)² = 36
Hope I helped ya!!
