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Let the positive integers be written in the form : [figure] If the kth row contains exactly k numbers for every natural number k, then the row in which the number 5310 will be, is .
103
Row k ends with 1 + 2 + + k = k(k + 1)2
k = 102: 102 1032 = 5253
k = 103: 103 1042 = 5356
Since 5253 < 5310 5356, the number 5310 lies in row 103 (which holds 5254 to 5356).
Answer: 103
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