The LCM of two numbers is 520 and their HCF is 13. How many such pairs of the numbers are formed?
Answer & explanation
Correct answer: option 2
LCM × HCF = Product of two numbers i.e. A × B
LCM = HCF (product of other factors i.e. a × b)
520 = 13(a × b)
a × b = 40
1 × 40 ....... (i)
2 × 20 ....... (ii)
4 × 10 ....... (iii)
5 × 8 ........ (iv)
(ii) and (iii), both have common factor 2
Therefore, possible factors are (i) 1 × 40 and (iv) 5 × 8