Verbal Reasoning - Mental Ability Questions

In a certain code language, '-' represents 'x', '÷' represents '+', '+' represents '÷' and 'x' represents '-'. Find out the answer to the following question.

12 - 2 + 6 x 20 ÷ 18 = ?

DWT : GZW :: QPM : ___

In the following series, one number is missing as shown by the question mark. Select the missing number from the given options.

8, 12, 16, 20, ?

Two labourers L and M start at the same point. L walks 10 m South, then turns left and walks 25 m. In the meanwhile M walks 20 m West, then turns to his right and walks 15 m , then turns East and walks 45 m. Where is M with respect to L?

In the following question, which one set of letters when sequentially placed at the gaps in the given letter series shall complete it?

b_d_ed_b_c_e

Two pickup trucks X and Y start from the same place. Truck X travels East 15 km and then turns right and travels 8 km. In the meanwhile truck Y travels 7 km West, then 3 km North, then 2 km West , then it turns left and travels 11 km. Where is truck Y with respect to truck X?

A student cycles 2 km North, then turns West and cycles 2.5 km, then turns South and cycles 2 km, then turns to his left and cycles 4.5 km. Where is he now with respect to the starting position?

The age of the father 4 years ago was 8 times the age of his son. At present, the father's age is 4 times that of his son. Find the present age of son.