Q24 of 51 Page 6

Find all pairs of consecutive even positive integers, both of which are larger than 5, such that their sum is less than 23.


Let the two consecutive even positive integers be x and x + 2.
x > 5, x + 2 > 5, x + (x + 2) < 23

x > 5, x + 2 > 5 ⇒x > 5.
 
2x + 2 < 23
2x < 21
x < 21/2

i.e 21/2 > x > 5

Thus, the required pairs of consecutive odd positive integers are (6, 8) and (8, 10).

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