13, a, b, c are four distinct numbers and the HCF of each pair of numbers (13,a); (13, c); (13,c) is 13, where a, b, c are each less than 60 and a< b < c. What is the value of $\frac{a+c}{b}$?
Answer & explanation
Correct answer: option 2
Four distinct numbers are 13, a, b, and c
a, b, c should be multiple of 13 as the HCF is 13
The HCF of 13 and a = 13 ⇒ a = 26
The HCF of 13 and b = 13 ⇒ b = 39
The HCF of 13 and c = 13 ⇒ c = 52
The value of $\frac{a+c}{b}$ = \(\frac{26 + 52}{39}\) = 2