Question

Suppose p varies directly as d, and p = 2 when d = 7. What is the value of d when p = 10?
A.)d=35
B.)d=15
C.)d=20/7
D.)d=7/5

Answer 1

p varies directly with d
so this equation can be written as:-
p=\(k\)d
where \(k\) is the constant of variation

2=7\(k\)
\(k\)=2/7

so when p is 10

10=\(k\)d
10=2/7*d
d=35