A mixture contains milk and water in the ratio 5:4. On adding 30 litters of water, the ratio of milk to water becomes 5:7. Total quantity of milk & water before adding water to it?
Choose the correct choice from the following options:
A) 90 B) 120 C) 80 D) 70 E) 60
Explanation:   milk: water = 5:4   5x : 4x + 30 = 5 : 7   7[5x] = 5[4x + 30]   35x = 20x + 150   35x - 20x = 150   15x = 150   x = 10   The quantity of milk in the original mixture is = 5 : 4 = 5 + 4= 
<gadget id="calculator">5 + 4</gadget>
<output>9</output>
9   9x= 90   Short cut method:   milk:water = 5 : 4   after adding 30 liters of water   milk:water = 5 : 7   milk is same but water increse 30liters then the water ratio is increse 3 parts   3 part -----&gt; 30 liters   The quantity of milk in the original mixture is = 5 : 4 = 5 + 4= 
<gadget id="calculator">5 + 4</gadget>
<output>9</output>
9   9 parts -----&gt; 9 liters (90nswer is= 90)   Short cut method - 2 : for Only milk problems   milk : water   5 : 4   5 : 7   milk ratio same but water ratio 3 parts incress per 30 liters   3 part of ratio -------&gt; 30 liters   1 part of ratio -------&gt; 10 liters   9 part of ratio ------&gt; 90 liters   90nswer: Option 90
<result>A</result>
A mixture contains milk and water in the ratio 5:4. On adding 30 litters of water, the ratio of milk to water becomes 5:7. Total quantity of milk & water before adding water to it?