Ratio and Proportion Solution9





In this page ratio and proportion solution9 we are going to see solution of each question from the worksheet ratio and proportion.

(11) If  A : B = 6 : 7 and B : C = 8 : 9,find A : B : C

Solution:

A : B = 6 : 7

B : C = 8 : 9

          = 1 : (9/8)

Now we are going to multiply by 7 with both antecedent and consequent

          =  1 (7) : (9/8) (7)

          =  (7) : (63/8)

A : B : C  = 6 : 7 :  (63/8)

                = 48 : 56 : 63     


(12) If 6 A = 5 B = 3 C , find A : B : C

Solution:

6 A = 5 B

A/B = 5/6

A : B = 5 : 6

5 B = 3 C

B/C = 3/5

B : C = 3 : 5

         = 1 : (5/3)              

Now we are going to multiply by 6

          = 1(6) : (5/3)6

          = 6 : 10

A : B : C = 5 : 6 : 10


(13) If (3 x + 1) : (9 x  + 4) is the duplicate of 4 : 7, find the value of x

Solution:

To find the duplicate ratio for 4 : 7 we have to take square

4² : 7²

16 : 49

(3 x + 1) : (9 x  + 4) = duplicate ratio of 4 : 7

(3 x + 1)/(9 x  + 4) = 16/49

49 (3 x + 1) = 16 (9 x + 4)

147 x  + 49  = 144 x  +  64

147 x – 144 x = 64 – 49

3 x = 15

x = 15/3

x = 5


(14) If (7 x + 1) : (13 x + 8) is the triplicate of 4 : 5, find the value of x

Solution:

 (7 x + 1) : (13 x + 8)  = triplicate of  4 : 5

(7 x +  1)/(13 x +8) = 4³/5³

 (7 x +  1)/(13 x +8) = 64/125

125 (7 x + 1) = 64 (13 x + 8)

875 x + 125 = 832 x + 512

875 x – 832 x = 512 – 125

43 x = 387

     x = 387/43

     x = 9

ratio and proportion solution9 ratio and proportion solution9