Cara, a blue whale participated in a weight loss program at the biggest…
2025
Cara, a blue whale participated in a weight loss program at the biggest office. At the end of every month, the decrease in weight from original weight was measured and noted as 1, 2, 6, 21, 86, 445, 2676. While Cara made a steadfast effort, the weighing machine showed an erroneous weight once. What was that?
- A.
2676
- B.
2
- C.
445
- D.
86
Attempted by 1046 students.
Show answer & explanation
Correct answer: D
This is a number series problem where each term follows a specific pattern.
The pattern is: term_n = term_{n-1} × (n-1) + (n-1).
Starting with 1:
1 × 1 + 1 = 2
2 × 2 + 2 = 6
6 × 3 + 3 = 21
21 × 4 + 4 = 88
88 × 5 + 5 = 445
445 × 6 + 6 = 2676
The fifth term in the given series is 86, but it should be 88. Therefore, 86 is the erroneous measurement.