M is inversely proportional to N. If M is 20, then N is 70. If N = 50, then what is the value of M?
Answer & explanation
Correct answer: option 3
M is inversely proportional to N. If M is 20, then N is 70.
M α \(\frac{1}{N}\)
⇒ M = \(\frac{K}{N}\) (K = constant)
when M = 20, N = 70,
20 = \(\frac{K}{70}\)
⇒ K = 1400,
Now when N = 50,
M = \(\frac{1400}{500}\)
⇒ M = 28.