1.
I am 48 (or even 104).
2. I am 26 now, and in 38 years I
will be 64 (which is both a square number and a cube number).
3. I am 9 years old now.
A
couple possible ways to solve question 3:
a)
Create a table and test the possibilities one by one.
My age
|
Mum’s age
|
My age now
|
Mum’s age eight years ago
|
My age in 5 years time doubled
|
|
0
|
27
|
||||
1
|
28
|
1
|
19
|
12
|
|
2
|
29
|
2
|
21
|
14
|
|
3
|
30
|
3
|
22
|
16
|
|
4
|
31
|
4
|
23
|
18
|
|
5
|
32
|
5
|
24
|
20
|
|
6
|
33
|
6
|
25
|
22
|
|
7
|
34
|
7
|
26
|
24
|
|
8
|
35
|
8
|
27
|
26
|
|
9
|
36
|
9
|
28
|
28
|
|
10
|
37
|
||||
11
|
38
|
||||
12
|
39
|
b) You could also solve an algebraic equation where x represents my age now.
x= my age now, so x + 27 is my mum’s age now.
x + 5 is my age in five years time.
2(x + 5) is my age in five years time doubled.
x + 27 – 8 is my mum’s age eight years ago.
So, 2(x+5) = x + 27 -8.
When you solve for x, you find that x=9.
