The far left column represents the 10's place and the digits to the right represent the 1's place.
look at the "3" row. How many digits are greater than 2? → <em>4,4,4,5,7 = 5 digits</em>
How many digits are in the "4" row (representing ages in their 40's)? → <em>6 digits</em>
How many digits are in the "5" row (representing ages in their 50's)? → <em>5 digits</em>
How many digits are in the "6" row (representing ages in their 60's)? → <em>4 digits</em>
How many digits are in the "7" row (representing ages in their 70's)? → <em>1 digit</em>
How many customers are older than 32? <em>5 + 6 + 5 + 4 + 1 = 21</em>
Answer: B