47. Even in respect of a geometrically progressive series, the common ratio and the first term are exactly alike (in the given series and in the chosen-off part thereof). There is (however) this difference here in respect of (the first term among the remaining number of terms (constituting the remaindor-series), viz., that the first term of the (given) series multiplied by that self-multiplied product of the common ratio, in which (product) the frequency of occurrence of the common ratio is measured by the chosen-off number of terms, gives rise to the first term (of the remainder-series).
Examples in illustration thereof.
48. Calculate what the sum of the remainder-series is in relation to that (series) of which is the common difference, the first term, and is (taken to be) the number of terms, when the chosen-off number of terms (to be removed) is (taken as) .
49. In relation to a series in arithmetical progression, the first term is , the common difference is , and the number of terms is (taken to be) . When the chosen-off number of terms (to be removed) is (taken as) , give out, O you who know calculation, the sum of the remainder-series.
50. What is the value of the sum of the remainder-series in relation to a series of which the first term is , the common difference is , and the number of terms is (taken to be) , when the chosen-off number of terms is ?
51. The first term is , the common difference is , and the number of tenums is (talken as) , and the chosen-off number of terms is taken to be or . O you, who, being the abode of kalās * , are the moon shining with the moon-light of wisdom, tell me the sum of the remaining number of terns .
52. Calculate the sum of the remaining number of terms in relation to a series of which the number of terms is 12, the common difference is minus , and the first term is , the chosen-off number of terms being 3, 4, 5 or 8.
7. See note under 110, Chap. II.
* Kāla is here used in the double sense of 'learning' and 'the digits of the moon'
