In a certain code, the symbol for 0 is $, for 1 is ∆ and for 2 is ●. There are no other symbols for all other numbers greater than 2. The numbers greater than 2 are to be written only with the help of the symbols given above. The value of 1 and 2 triples every time it shifts one place to the left. Study the following examples:
0 is written as $ 1 is written as ∆ 2 is written as ●
3 is written as ∆ $ 4 is written as ∆ ∆ 5 is written as ∆ ●
6 is written as ● $ and so on

1. Which of the following will represent ● ∆ $ ● ∆ $?
(a) 588 (b) 593 (c) 592 (d) 591

2. Which of the following will be code for 319?
(a) ∆ ∆ ● ● ∆ ∆ (b) ∆ $ ● ● ∆ ∆ (c) ∆ ∆ ● ● $ ∆ (d) ∆ ● ∆ ● ● $

3. Which of the following numbers will be represented by ● ● ∆ ∆ $ $?
(a) 304 (b) 407 (c) 684 (d) 683