gmatophobia
DS Question 1 - Sep 19 If x is a positive integer less than 30, is x odd? (1) When x is divided by 3, the remainder is 2. (2) When x is divided by 5, the remainder is 2. Difficulty: Hard | Source: Veritas Prep
1) x/3 gives R2. In this case, x can be expressed as: x=3k+2 where k is any integer.
If k is 0, x=2
If k is 1, x=5
INS
2) Similarly, x can be expressed as x=5k+2
If k is 0, x is 2
If k is 1, x is 7.
Ins.
3) If x is not divisble by both 3 and 5, it can be expressed as:
x=15k+2
Here we can have:
x=2 or 17.
Still no definite value, so ins
E.
90x=T <- amount of days "x" that lets you finish the book at a rate of 90
75(x-6)+690=T <- reading at 75 pages for (x-6) days you have 690 in excess to read before finishing the book
Equate the two
75x+240=90x
15x=240
x=16