1.  What is the time required to punch 1500 cards of 45 column each at the rate of 9,000 punches per hour ?
A. 8 hrs
B. 7 hrs 15 min
C. 7 hrs 30 min
D. 8 hrs 20 min

Answer: Option C

Explanation:

Total number of cards = 1500

Total columns = 45

so, total punches=1500 x 45 = 67500

for 1 hour if we make 9000 punches,

we require 67500/9000 = 7.5

so 7hours:30mins.