Q668
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
AnswerAnswer: Option D
Solution
Answer: Option D
Solution:
121 to 999 - 3 digitTotal 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