Hello everybody! This is my first time joinning here
I have 2 questions below to ask....I know the answer but I don't know how to do it! I will come back and post the answer tomorrow..
1. What is the remainder when the positive integer x is devided by 8?
(1) When x is divided by 12, the remainder is 5.
(2) When x is divided by 18, the remainder is 11.
2. In the decimal representation of x, where 0<x<1, is the tenths digit of x nonzero?
(1) 16x is an integer.
(2) 8x is an integer.
1. from (1): x = 12n + 5 . Since n ould be any integer, x could be the sum of 5 and any multiple of 12. Not SUff!
from (2) x = 18m + 5 . Same logic as above. Not SUff
(1) and (2) --> 2 equations, 3 unkowns. not Suff! E it is
from 1: 16x could be 1, 2, 3 etc. the smallest value of x (if tenths digit is 0, the number is smaller than if it is not) would be 1/16 = .0625. for 2, 3, 4... the tenths digit is non zero. Since we have both cases Not suff!
from 2: similarly, 1/8 = .125 for 2/8 3/8 etc the tenths digit has to be nonzero as well since they will be larger than .125. Sufficient
B is the answer