Question

8. I)Two brothers have their annual incomes in the ratio 8:5 their spending in
the ratio 5:3. If they save Rs.2400 and Rs. 2000 per annum, find their
incomes.
11) If A = {1,2,3), B = (2,3,4). Find (A x B) - (B x A) ?
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Answer 1

Answer:

let x = the 1st multiplier

then

8x = A's income

and

5x = B's income

:

let y = the 2nd multiplier

then

5y = A's expenditures

and

3y = B's

:

write an equation for each

8x - 5y = 1200

5x - 3y = 1000

multiply the 1st equation by 3, multiply the 2nd equation by 5

rearrange to

25x - 15y = 5000

24x - 15y = 3600

-----------------subtraction eliminates y, find x

x = 1400 is the 1st multiplier

therefore

8*1400 = $11200 is A's income

and

5*1400 = $7000 is B's income