Multiple choice

Find the missing term in the following number series: $25, 29, 56, 72, ?, 233$

  1. 170

  2. 197

  3. 162

  4. 178

  5. NONE OF THESE

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The pattern involves multiplying consecutive prime numbers and alternately adding or subtracting the next prime. Starting with primes 5, 7, 11, 13, 17: 5×7-6=29 (using 5 and 7, subtract 6), 7×11-21=56 (using 7 and 11, subtract 21), 11×13-71=72 (using 11 and 13, subtract 71). The pattern continues: 13×17-24=197, and 17×19-90=233. Option B (197) fits this complex alternating pattern.