Answer:
sister = 6 years
John=18 years
Step-by-step explanation:
A(S) + 12 = 3 * A(S), subtracting A(S) from both sides one gets 12 = 2 * A(S). Now dividing both sides by 2 we get A(S) = 12/2 = 6 . Therefore, the age of the sister is 6 years when her brother John is three times as old, that is 18 years.
Answer:
5
Step-by-step explanation:
[math]
U_{n} = 5n - 2 \\
Common Difference = U_{n+1} - U_{n} \\
= [5(n + 1) - 2] - [5n - 2] = [5n + 5 - 2] - [5n - 2]\\
= 5n + 5 - 2 - 5n + 2\\
= 5
[/math]
