1. Two is the only prime number; all of the other primes are odd. Hence any two consecutive odd primes must differ by at least 2, as do 3 and 5, and 5 and 7. Prime numbers that differ by exactly 2 are called twin primes. Find three pairs of twin primes other than those already mentioned.
2. Numerals 37 and 73 arc prime numbers with reversed digits. What are the other pairs of two-digit primes with reversed digits that are less than 100?
3. Find the greatest common divisor for each of the following:
(a) 24, 48, and 60
(b) 111 and 267
4. Find the least common multiple for each of the following:
(a) 48 and 72
(b) 234 and 470
5. Evaluate each of the following
(a) (12)(2) ÷ 4 + 8 - 2
(b) 2 x 4 + 5-6 ÷ 3
6. From the set of numbers {1, 4, 5, 7, 9, 12, 15), Write down
(a) the prime numbers
(b) multiples of 3
(c) factors of 60
7. Express each of the following numbers as a product of the prime factors and hence find its square root without using a calculator.
(a) 3136
(b) 441
8. Exploit the commutative, associative and distributive laws of real numbers to evaluate the following mentally
a) (5)(297)
b) (19)(20)
9. For the given equation, name the property that is illustrated by the equation
a) -5 + 9 = 9 + (-5)