In a colony the municipality decided to number the houses and the shops. They want to number the shops with the numbers containing 3 between 1-100. The houses are 10-20 floored and at the back of the houses 8 feet is left for fire exit. How many shops can be numbered?
Choose the correct choice from the following:
A) 19  B) 20  C) 21  D) 22  E) 23

Rationale: 3 numbers containing 3 - - - > 3 , 1323 , . . . = 10 numbers - - - - > 30 , 3132 . . . = 10 numbers total = 20 - 1 = 19 answer : a
Answer: A