2014 · Q16
How many pairs of positive integers m and n satisfy the equation 1/m + 4/n = 1/12, where n is an odd integer less than 60?
Elementary MathematicsNumber System
- A7
- B5
- C4
- D3
Explanation
m = 12n/(n − 48) with n odd, 48 < n < 60. Integer m occurs for n = 49 (m = 588), 51 (m = 204), 57 (m = 76): 3 pairs.