Question

A) How many 2-digit numbers have the digit 7 exactly once?

Answer 1

17, 27, 37, 47, 57, 67, 87, 97.
8

Explanation:

all are 2 digit numbers with exactly one 7 in each.

Answer 2

8

Explanation:

the two digit numbers that has 7 exactly

once are 17, 27, 37, 47, 57, 67, , 87, 97

from above, there are 8 two digits