EXPLANATION

QUESTION NO:1

Number of runs made by running = 110 - (3 x 4 + 8 x 6)

= 110 - (60)

= 50.

 Required percentage =((50*100)/110)= (45*(5/11))%

QUESTION NO:2

Let their marks be (x + 9) and x.

Then, x + 9 = {(56/100)(x + 9 + x)}

 25(x + 9) = 14(2x + 9)

 3x = 99

 x = 33

So, their marks are 42 and 33.

QUESTION NO:3

Suppose originally he had x apples.

Then, (100 - 40)% of x = 420.

(60/100) x x = 420

 x = {(420 x 100)/60}  = 700.

QUESTION NO:4

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)/70}= 20%.



QUESTION NO:5

x% of y = {(x/100)* y}= {(y/100)* x}= y% of x

 A = B.

So answer is none of these


NOTE: * MEANS MULTIPLICATION