Answer:
25 math problems
Step-by-step explanation:
He completed 10 out of x, or the total he has to do.
10/x
We know that this equals 40%
10/x=40/100
Cross multiply to solve
40*x=100*10
40x=1000
Divide both sides by 40
x=25
He must do 25 math problems
Answer:
300
(second answer choice)
Step-by-step explanation:
Recall that the Z-distribution is defined as :

and therefore, to obtain a Z = 2.5 when the mean value
=200, and the standard deviation
= 40 , we solve for "X":
