Question

the incomes of M andN are in the ratio of 8:7 and their expenditures are in the ratio of 5 :4 they both save 21000ruppess every month what is the income of each of them​

Answer 1

Given: Incomes of M and N are in the ratio of 8:7,

           their expenditures are in the ration of 5:4,

           they save Rs. 21000

To find: Income of M and N

Step-by-step explanation:

Let the income of M and N be Rs. 8x and Rs. 7x

Ratio = $\frac{8x}{7x} = \frac{8}{7}$

Each of them save Rs. 21000 every month, then the expenditures of M and N  are Rs. 8x - 21000 and Rs. 7x - 21000 respectively

Ratio of their expenditures =

 $\frac{8x - 21000}{7x - 21000} = \frac{5}{4}\\4\times(8x - 21000) = 5\times (7x - 21000)\\32x - 84000 = 35x - 105000\\ 35x - 32x = 105000 - 84000\\3x = 21000\\x = \frac{21000}{3}\\x = 7000$

Hence, the monthly income of

M = $Rs. 8\times 7000 = Rs. 56000$

N = $Rs. 7 \times 7000 = Rs. 49000$