EXERCISE 4 (OBJECTIVE TYPE QUESTIONS SOLUTION IN 51 60)

51.       Given equation is: (5X + 1) / X x (4y + 3)/4 =20

(5X+ 1) (4y + 3) = 80X ….(I)

Clearly, X = 3 and y = 3 satisfy (I)

52.       Required difference = 19/16 – 16/19 =19² - 16²/304 = (19 + 16) (19 -16)/304 =35 x 3 / 304 = 105 /304.

53.       Required number = 37  1/2 /  1/8 = 75/2 / 1/8 = 75/2 x 8 = 300.

54.       Let X of 1/12 = 3/8. Then, X/12 = 3/8

       X = (3/9 x 12) = 9/2.

55.       Sum of given fractions = 7/4 + 5/2 + 67/12 + 10/3 + 9/4 = ( 21 + 30 + 67 + 40 + 27/12) = 185/12

The whole number just less than 185 /12 is 15.

Let 185/12 –X =15. Then, X =(185/12 – 15) =5/12.

56.       Clearly, X + 1/X is the only fraction in which the numerator is greater than the denominator. So, it is the greatest fraction.

57.       3/5 of 350 – 4/7 of 210 -120 =90.

v

58.       6/7/8 – 6/7 / 8 = 6 x 8/7 -6/7 x 1/8 = 48/7 – 6/56 = 384 – 6/56 = 378 / 56 = 27/4 = 6 3/4

59.       Let the value of the estate be Rs. X.

        The, 4/5 of X = 16800

        X =(16800 /4) = 21000

        3/7 X = (3/7 x 21000) = 9000.

60.   Let the number be x. then.

2/5 of ¼ of 3/7 of X = 15

                             X = ((15 x 7/3 x 4 x 5/2) = 350 1/2 X = 175.