2018 · Q14
There are two numbers which are greater than 21 and their LCM and HCF are 3003 and 21 respectively. What is the sum of these numbers?
Elementary MathematicsNumber System
- A504
- B508
- C514
- D528
Explanation
Write the numbers as 21a and 21b with coprime a, b (both exceed 1 since the numbers exceed 21). Their LCM is 21ab = 3003, so ab = 143 = 11 × 13. The numbers are 21×11 = 231 and 21×13 = 273, whose sum is 504, option (A).