Explain why `7/9 + 7/9` does not equal `14/18`.

Explain why   3 xx 5 xx 7 xx 9 xx 11 +11   is a composite number.

(9!-8!)/(7!) is equal to

If A = { 5,6,7 } and B = { 7, 8, 9 } , then A uu B is equal to :

Evaluate : 1/2 times 4/9 + 7/9 times 9/4 + ( -6/7 ) times 9/2

Find x, if 4xx(7)/(9) = (7)/(9) xx x .

The mean deviation of the data 2, 9, 9, 3, 6, 9, 4 from the mean is : A. (42)/(7) B. (18)/(7) C. 2.5 D. (50)/(7)

Study the following arrangement carefully and answer the questions given below: 6 7 8 9 9 8 7 9 7 7 8 9 7 8 7 6 9 6 8 9 7 7 9 8 9 7 6 8 8 7 How many such seven are there in the given series each of which is immediately preceded by 9 and also immediately followed by 8? 1) None 2 ) One 3)Two 4)Three 5)More than three

Study the following arrangement carefully and answer the questions given below: 6 7 8 9 9 8 7 9 7 7 8 9 7 8 7 6 9 6 8 9 7 7 9 8 9 7 6 8 8 7 Which of the following number is obtained when 18th number from the left to the number series is added to 19th from the right? 1) 15 2 ) 20 3)10 4)17 5)None of these