A tire maker codes tires with four symbols using numbers 1 through 4

[m.gayatri]

A tire maker codes tires with four symbols using numbers 1 through 4 and the letters A through D.Each code has two numbers and two letters .The two numbers must be next to each other and the two letters must be next to each other .The two letters must be different .The numbers on the right must be more then one on the left .

1. If the fourth symbol is 3 ,what could be the third symbol be ?
A) A B) B C) C D) 1 E) 4

2. If the letter A occurs ,what must be also true ?
A) B also occurs B) C also occurs C) D also occurs D)A occurs once E)A occurs twice

3. If 2 is the first symbol,which of the following could not be in one of the other three positions
A) 1 B) 3 C) 4 D) C E) D