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The sum of a pair of positive integer is 336 and their H.C.F. is 21. The number of such possible pairs is
- A2
- B3
- C4
- D5
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CCommunity
3 : - option 3
0
CCommunity
Let the numbers be 21x and 21y where x and y are prime to each other.
21x + 21y = 336
21 (x + y) = 336
x + y =$\frac{336}{21}$ = 16
Possible pairs = (1, 15), (5, 11), (7, 9), (3, 13)
21x + 21y = 336
21 (x + y) = 336
x + y =$\frac{336}{21}$ = 16
Possible pairs = (1, 15), (5, 11), (7, 9), (3, 13)