Ratio and Proportion Solution10





In this page ratio and proportion solution10 we are going to see solution of each question from the worksheet ratio and proportion.

(15) If a : b = 3 : 2 and b : c = 5 : 8,find  a: c and a : b : c .

Solution:

a : b =3 : 2

a/b = 3/2

b : c = 5/8

b/c = 5/8

we can write a : c as (a/c)  => (a/b) x (b/c) = (3/2) x (5/8)

                                         (a/c) = (15/16)

                                          a : c = 15 : 16                                        

a : b =3 : 2

       = 1 : (2/3)

Now we have to multiply by 15, 

          =  1(15) : (2/3) (15) : 16 (15)

          = 15 : 10 : 240

We can simplify this by 5,so we get

a : b : c = 3 : 2 : 48


(16) If x : y = 5 : 7 and y : z = 4 : 5, find x : z and x : y : z

Solution:

x : y = 5 : 7

x/y = 5/7                      

y : z = 4 : 5

 y/z = 4/5                         

we can write x : z as (x/z) => (x/y) x (y/z) = (5/7) x (4/5)

                                     (x/z) = (4/7)

                                      x : z = 4 : 7            

y : z = 4 : 5

        = 1 : (5/4)

Now we are going to  multiply it by 4, so we get

         = 4 : (5/4) x 4                  

         = 4 : 5         

x : y : z = 4 : 4 : 5


(17) If x : y = 2 : 1 find (5 x + 8y) : (6 x – 7y)

Solution:

x : y = 2 : 1

x/y = 2/1

(5 x + 8y) : (6 x – 7y) =  (5 x + 8 y) /(6 x – 7 y)

Divide both numerator and denominator by x, so we get 

                                     = [5 + 8(x/y)]/[6  – 7(x/y)]

                                     = [5 + 8(2/1)]/[6  – 7(2/1)]

                                     = [5 + 16]/[6  – 14]

                                     = 21/[– 8]

                                     = -21/8

Therefore the value of (5 x + 8y) : (6 x – 7y)is -21/8

ratio and proportion solution10 ratio and proportion solution10