<u>Answer:</u>
- The first four terms are <u>4</u><u>,</u><u>8</u><u>,</u><u>1</u><u>2</u><u>,</u><u>1</u><u>6</u>
<u>Step-by-Step </u><u>Explanation</u><u>:</u>
The given relation between the nth term and it's previous term is given by:

GiveN:
Now finding the other three terms of the AP with the given relation.

Putting a1 = 4,

Now, Third term:

Putting a2 = 8,

Now, Fourth term:

Putting a3 = 12,

Hence, The first four terms of the AP is 4, 8, 12 & 16.
Answer:
12 pull
As 48 seconds + 20 seconds push = 68 seconds
Step-by-step explanation:
Because she did 10 push = 20 seconds = 2 seconds each
12 pull = 48 seconds = 4 seconds each
= 68 seconds combined.
Workings;
18 seconds found for the first set
We then find a divider of 68 and know that
6 x 3 = 18 seconds push
12 x 3 =36 seconds pull T= 54
14 left over = 1 x 12 seconds pull
+ 2 seconds push
= 10 push = 20 seconds combined.
= 12 pull = 48 seconds combined.