Question

MINIMO MULTIPLO COMUM
90, 15, 60

Answer 1

10: {10, 20, 30, 40, 50, 60, 70, 80, ... }
12: {12, 24, 36, 48, 60, 72, 84, .... }
15: {15, 30, 45, 60, 75, 90, ...}
Portanto, mmc(10, 12, 15) = 60.

Answer 2

90, 15, 60 | 2
45, 15, 30 | 2
45, 15, 15 | 3
    15, 5, 5 | 3
      5, 5, 5 | 5                                                 
      1, 1, 1 | 2² * 3² * 5 = 4 * 9 * 5 = 180

Espero ter ajudado. Valeu!