Which of the following sentences are statements? Give reasons for your answer?

(i) There are 35 days in a month.

(ii) Mathematics is difficult.

(iii) The sum of 5 and 7 is greater than 10.

(iv) The square of a number is an even number.

(v) The sides of a quadrilateral have equal length.

(vi) Answer this question.

(vii) The product of –1 and 8 is 8.

(viii) The sum of all interior angles of a triangle is 180° .

(ix) Today is a windy day.

(x) All real numbers are complex numbers.

(ii) The given sentence is not a statement because for some people mathematics can be easy and for some it can be difficult.

(iii) The given sentence is always true because the sum is 12 and it is greater than 10. Therefore it is a statement.

(iv) The given sentence is sometimes true and sometimes is not true. For example the square of 2 is an even number and the square of 3 is an odd number. Therefore it is not a statement.

(v) The given sentence is sometimes true and sometimes false. For example, the squares and rhombus have equal length whereas rectangles and trapezium have unequal length. Therefore it is not a statement.

(vi) It is a command and therefore it is not a statement.

(vii) This sentence is false as the product is (-8). Therefore it is a statement.

(viii) This sentence is always true and therefore it is a statement.

(ix) It is not clear from the context which day is referred and therefore, it is not a statement.

(x) This is a true statement because all real numbers can be written in the form a + ix0.