x varies directly as y and inversely as z. when x = 5, y = 2 and z = 1. What is the value of x when y = 5 and z = 2?
A
2.5
B
5
C
6.25
D
6.52
E
7.5
Verified Correct Answer: C.
Step-by-Step Mathematical Solution
x = \(\frac{ Ky}{z}\)
x = 5, y = 2 and z = 1
x = \(\frac{ Ky}{z}\)
5 = \(\frac{ K2}{1}\)
K = \(\frac{5}{2}\) = 2.5
find x when y = 5 and z = 2
x = \(\frac{2.5 \times5}{2}\)
x = \(\frac{12.5}{2}\) = 6.25.
Source: Myschool Past Questions Archive (Record #42514)