1. (a) (x − 2) is a factor of the expression x3 + ax2 + bx + 6. When this expression is divided by (x − 3), it leaves the remainder 3. Find the vlaues of a and b. (Type in the answers separated by commas. Leave no spaces around the commas.)   2. (b) What number must be added to each of the numbers 6, 15, 20 and 43 to make them proportional?   3. (c) If the interest is compounded half yearly, calculate the amount when the Principal is Rs 7,400, the rate of interest is 5% per annum and the duration is one year.