TCS
Company
Numerical Ability
Log and Antilog
The citizens of planet Oz are fingered and thus have developed a number system in base 6. A certain street in Oz contains 1000 buildings numbered from 1 to 1000. How many 2’s are used in numbering these buildings? Express your answer in base 10.
(a) 144
(b) 24
(c) 108
(d) 36
Read Solution (Total 2)
-
- they have 6 finger so their number system include 0-5 digit;
so countings are like this...0-5,10-15,20-25 and so on...
for upto 100.... 0-5 include 0ne 3,10-15 includes one 3,
like this 20-25=1,30-35=7(because 10th place also have 3),40-45=1,50-55=1
therefore total 12 3...lyk this for 100-155=12,200-255=12,300-355=12+36(since here 100th place is also included),400-455=12,500-555=12
total=12*6+36=108 - 13 years agoHelpfull: Yes(30) No(6)
- Formula: (N-1)*(BASE)^(N-2)
N=NUMBER OF LAST DIGIT=4(100 contains 4 digits)
base=6
(4-1)*6^(4-2)
=108
- 9 years agoHelpfull: Yes(1) No(1)
TCS Other Question