Directions: Find the wrong number in the following number series. 11, 58, 111, 171, 231, 298, 369

The differences between the consecutive terms are calculated to identify the underlying pattern. The differences are 58 minus 11 equals 47, 111 minus 58 equals 53, 171 minus 111 equals 60, 231 minus 171 equals 60, 298 minus 231 equals 67 and 369 minus 298 equals 71. The correct pattern of differences should be an arithmetic progression increasing by 6, which means the differences should be 47, 53, 59, 65, 71 and 77. Since 111 plus 59 equals 170, the number 171 is incorrect and the right term should have been 170, making 171 the wrong number.

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