Question

In a certain city, all telephone numbers have six digits, the first two digits always being 41 or 42 or 46 or 62 or 64. The number of telephone numbers having all six digits distinct is

Answer 1

Answer:

120

Step-by-step explanation:

first two digits are we know...

remaining four digits are 4! times...

4!=4×3×2×1=24

total 5 types are there....

so 5×24=120