The circuit shown in figure is using one 4-bit BCD counter and one 4-bit binary counter. The MOD value for the counter is ?
I think the answer is 80.
BCD counter counts from 0-9 and starts again (mod 10).
Binary counter counts from 0-15 and starts again (mod 16)
Lets assume initially Binary counter at value 0000.
BCD counter can count on clock pulses, Binary counter increments only when Q3 becomes 1 (ie 8 and 9)
See the figure , I am including, we have 8 cycles of 10 different values . Therefore answer is 80.