plz answer this

The Second term is -186 and the fifth term is 40176 . a) Find the common ratio. (1 marks) b) Find the first term a. ( 0.5 marks) c) Find the sum of the first 6 terms. (1 marks) Question 3 (2 marks) A machine was purchased 4 years ago at 770OMR. The annual value of the machine decreases continuously at a rate of 6.8%. a) What is the current value of the machine? (0.5 marks) b) What will be the value of the machine after 3 years. ( 0.5 marks) c) After how many years will the value of the machine become a half of its current value? (1 marks)