A certain JK flip-flop has tpd = 12 n sec. What is the largest

A certain JK flip-flop has tpd = 12 n sec. What is the largest MOD counter, that can be constructed from these FFs and still operate upto 10 MHz?

f ≤	1
	nt_pd

or MHz ≤	1
	n × 12 × 10^-9

or 10×10⁶ ≤	1
	n × 12 × 10^-9

or n ≥	1000
	120

or n ≥ 8.33 or n = 8
The largest MOD counter = 2⁸ = 256.