Xavier Aptitude Test 2011 Paper

(a) All the nos which have 5 in it are skipped by the meter.
From 0000 to 0099
5 occurs 10 times in 10’s place
5 occurs 10 times in units place, (which includes the number 55)
∴ Total no. of numbers that have 5 = 10 + 10-1 = 19
Similarly, no. of numbers that have 5 in them
From 0100 to 0199 ⇒ 19
0200 to 0299 ⇒ 19
0300 to 0399 ⇒ 19
0900 to 0999 ⇒ 19
........⇒ 19
........⇒19
........⇒19
0900 to 0399 ⇒ 19
= 8 ×19
The micromanometer will skip all the 100 nos. between 0500 and 0599 as the reading would change from 0499 to 0600.
∴Total no of nos. skipped from 0000 to 0999 = 19 (9) + 100 = 271
Similarly, from 1000 to 1999 and from 2000 to 2999, 271 + 271 numbers are skipped.
between 3000 and 3016
3005 and 3015 are skipped.
∴ Total numbers that have been skipped by the meter = 271 × 3 + 2 = 815
∴ Actual pressure inside the gas = 3016 – 815 = 2201