Which of these are multiples of three? Explain why. 20 15 49 13

Calculate and write, step by step, the process for arriving at the solution. (50 : 5 – 23 )2 + 3 · (6 · 3 – 4 · 4)3

The bus on line A passes a certain stop every 12 minutes, the bus on line B passes every 18 minutes, and the bus on line C passes every 24 minutes. If they all coincide at 10 a.m., at what time do they coincide again?

Calculate: mín.c.m. (12, 24, 36)

Calculate and write, step by step, the process for arriving at the solution.                                   [(56 : 7 – 6)3 + 4]2 : (8 – 5)2

Calculate: máx.c.d. (60, 72, 84)

Silvia visits her grandmother every 8 days and her brother Alberto every 14 days. When will they visit each other again? How many visits will each of them have made to their grandmother?

Calculate and write, step by step, the process for arriving at the solution. 81 : [(16 · 4 – 5 · 8)2 : (12 – 4)2]

Is the number 64 a multiple of 4? Explain.

Is the number 13 a divisor of 64? Explain.

Which of these are multiples of 2? 20 455 352 495 462 909

Calculate and write, step by step, the process for arriving at the solution.

Which of these numbers are multiples of two and three at the same time? 120 455 352 495 462 909