Question

10000,11000,9900,10890,9801,............

Answer 1

10781.

10000+1000 is equal to 11000

11000-1100 is equal to 9900

9900+990 is equal to 10890

10890-1089 is equal to 9801

9801+980 is equal to 10781

Answer 2

Answer:

The next number of the given series is 10781.

Solution:

Whenever a series is given check whether the series follows an operational pattern. Logically in this series, the pattern followed is alternative addition and subtraction with the number neglecting the zero in the units place of the given number. Therefore, the pattern followed by the given series is,

10000+1000=11000

11000-1100=9900

9900+990=10890

10890-1089=9801

Similarly,

9801+980=10781