








Explanation: Let their marks be (x + 9) and x.
Then, x + 9 =  56  (x + 9 + x) 
100 
25( x + 9) = 14(2 x + 9) 3 x = 99 x = 33 So, their marks are 42 and 33. 
3.  A fruit seller had some apples. He sells 40% apples and still has 420 apples. Originally, he had:
Answer: Option D
Explanation:
Suppose originally he had x apples.
Then, (100  40)% of x = 420.
 60  x x = 420 
100 
4.  What percentage of numbers from 1 to 70 have 1 or 9 in the unit's digit?
Explanation:
Clearly, the numbers which have 1 or 9 in the unit's digit, have squares that end in the digit 1. Such numbers from 1 to 70 are 1, 9, 11, 19, 21, 29, 31, 39, 41, 49, 51, 59, 61, 69.
Number of such number =14
Required percentage =   14  x 100  % = 20%. 
70 

5.  If A = x% of y and B = y% of x, then which of the following is true?
Answer: Option E
Explanation:
x% of y =   x  x y   =   y  x x   = y% of x 
100  100 
A = B. 


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