How many times the keys of a typewriter have to be pressed in order to write number from 121 to 1346?

A. 3675

B. 4018

C. 4021

D. 4025

Answer: Option D

Solution(By Examveda Team)

121 to 999 - 3 digit
Total number of terms = 999 - 121 + 1 = 878 + 1 = 879
Total keys from 121 to 999 = 879 × 3 = 2637
1000 to 1346 - 4 digit
Total number of terms = 1346 - 1000 + 1 = 347
Total keys from 1000 to 1346 = 347 × 4 = 1388
Total keys = 2637 + 1388 = 4025