EXERCISE 4 (OBJECTIVE TYPE QUESTIONS SOLUTION IN 61 70)

61.       Let the number be X. then,

1/5 X -1/7 X =10

7X – 5X /35 = 10

2X /35 =10

X = (10 x 35/2)  = 175.

62.       9 * 11 =9² + (11)² -9 11 = 81 + 121 -99 =103.

63.       (3* -1) = 3 x (-1) / (3 + (-1) = -3/2. So, 3* (3* -1) =3* (-3/2) = 3 x (-3/2)/3 + (-3/2) = -9/2 x 2/3= -3.

64.       3 * 5 + 5+ 3 = ( 2 x 3 – 3 x 5 + 3 x 5) + (2 x 5 -3 x 3 + 5 x 3)

= ( 6 + 10 – 9 + 15) = 22.

65.       4 + (3 + p) = 4 + (3² + 2p) =4 + (9 + 2p) =4² + 2 (9 + 2p) =34 + 4p.

34 + 4p =50

4p =50 -34 =16

P=4.

66.       (a * b * c) * a * b = ( a + b /c) * a * c = ( a + /c /b = a + b + ac/b c

67.       Let the number be X. then,

5 ( X + 7)  /9 – 3 = 12

5 (X + 7) -27 =108

5X + 35 = 135

5 X = 100

X =20.

68.       Given exp. = (5/7 x 19/13 ) ÷ ( 19 /7 x 4/13) = 5 x 19 / 7x 13 x 7 x 13 /19 x 4 =5/4.

69.       Given exp. = 11/4 ÷ 8/3 ÷ 13/12 = 11/4 x 3/8 x 12/13 = 99/104.

70.   Given exp. = 9/2 x 13/3 – 25/3 ÷ 17/3 = 9/8 x 13 x 3 – 25 / 3 x 3/17.

= 39/2 – 25 / 17 = 663 – 50 / 34 = 613 / 34 = 18 1/34.