maths quiz questions

The periodicity of 4627.428571, is : 1. 4 2. 10 3. 6 4. 19

The period in 690.384615, is : 1. 384615 2. 690 3. 690384615 4. 6

If the denominator of a fraction in its lowest terms, has no other prime factors except 2 and 5, then : 1. it can be expressed as a terminating decimal 2. it can be expressed as a non-terminating but repeating decimal 3. it can be expressed as a non-terminating and non repeating decimal 4. all of these

The set of numbers that possess the property of density, is : 1. Z 2. Q 3. R 4. 2 and 3