CMAT Linear Equations Questions

Let price of banana be x 
so price of orange = 3x 
and price of apple will be 6x
Price of 20 bananas , apples and oranges = 200 x  (1)
Now f the price of an apple increases by 10%,
it becomes = 6.6x
so price of 20 apples = 132x
if price of an orange increases by 30% it becomes = 3.9x
so price of 20 oranges = 78x
if price of a banana increases by 20%
it becomes 1.2 x
so price of 20 bananas = 24x
Now total price of 20 bananas , apples and oranges =234x  (2)
So Percentage change in price = $$\frac{234x-200x}{200x}\times\ 100=\ 17$$%

Let the three consecutive odd numbers be 'x-2', 'x' and 'x+2'

Given the sum of three consecutive odd numbers is 20 more than the first number

$$\Rightarrow$$ x-2 + x + x+2 = 20 + x-2

$$\Rightarrow$$ 2x = 18

$$\Rightarrow$$ x = 9

Therefore the three consecutive odd numbers are 7,9 and 11.

The middle number is 9.

Let the cost of each orange, banana and apple be Rs. 'o' , 'b' , and 'a' respectively.

Given, Two oranges, three bananas and four apples cost Rs. 15

$$\Rightarrow$$ 2o + 3b + 4a = 15..........(1)

Also given, Three oranges, two bananas and one apple cost Rs. 10

$$\Rightarrow$$ 3o + 2b + a = 10............(2)

Adding (1) and (2), we get,

5o + 5b + 5a = 25

$$\Rightarrow$$ o + b + a = 5

Then the cost of three oranges, three bananas and three apples is given as

3o + 3b + 3a = 3 [o + b + a] = 3$$\times$$ 5 = Rs. 15 

Given AB + C = D................................(1

If B = 6 and D = 30,  then from (1),

6A + C = 30........................(2)

and If B = 8 and D = 36,

8A + C = 36........................(3)

(3)-(2) => 2A = 6

=> A= 3

Substituting the value of A in equation (2) we get,

18 + C = 30

=> C = 12.