State whether the following statements are true (T) or false (F):

(i) If x is variable then 5x is also variable.

(ii) If y is variable then y − 5 is also variable.

(iii) The number of angles in a triangle is a variable.

(iv) The value of an algebraic expression changes with the change in the value of the variable.

(v) If the length of a rectangle is twice its breadth, then its area is a constant.

(vi) An equation is satisfied only for a definite value of the variable.

(vii) If x toffees are distributed equally among 5 children, then each child gets 5x toffees.

(viii) t minutes are equal to 60t seconds.

(ix) If x is a negative integer, then −x is a positive integer.

(x) x = 5 is a solution of the equation 3x + 2 = 13.

(xi) 2y - 7 > 13 is an equation.

(xii) 'One third of a number x added to itself gives 8' can be expressed as $\dfrac{x}{3} + 8 = x$.

(xiii) The difference between the ages of two sisters Lata and Asha is a variable.

I think of a number x, add 5 to it. The result is then multiplied by 2 and the final result is 24. The correct algebraic statement is

1. x + 5 × 2 = 24

2. (x + 5) × 2 = 24

3. 2 × x + 5 = 24

4. x + 5 = 2 × 24

If each matchbox contains 48 matchsticks, then the number of matchsticks required to fill n such boxes is

1. 48 + n

2. 48 − n

3. 48 ÷ n

4. 48 n

If the perimeter of a regular hexagon is x metres, then the length of each of its sides is

1. (x + 6) metres

2. (x − 6) metres

3. (x ÷ 6) metres

4. (6 ÷ x) metres