ssccglapex

From a container, full of pure milk, 20% is replaced by water and this process is repeated three times. At the end of third operation, the quantity of pure milk reduces to:

A. 40.0% B. 50.0% C. 51.2% D. 58.8% Answer: Option C
Show Answer

Solution(By Apex Team)

Let pure milk was 100L. So, Water is replaced 20% in per process = 20% of 100 = 20L. Now, we use short-cut formula for it. Quantity of Milk reduced to, $\begin{aligned}&=\mathrm{X}\times\left[1-\frac{\mathrm{Y}}{\mathrm{X}}\right]^{\mathrm{n}}\\ &=100\times\left[1-\frac{20}{100}\right]^3\\ &=\frac{100\times64}{125}\\ &=51.2\%\end{aligned}$ Here, X = Initial quantity of milk. Y = Replaced water in per process. n = No. of process repeated.
Alternatively, Let pure milk be 100 litres initially. After third operation, milk will be 100 = 20%↓(- 20L) ⇒ 80 = 20%↓(- 16L) ⇒ 64 = 20%↓(-12.8L) ⇒ 51.2 %

Related Questions On Alligation


The ratio, in which tea costing Rs. 192 per kg is to be mixed with tea costing Rs. 150 per kg so that the mixed tea when sold for Rs. 194.40 per kg, gives a profit of 20%.

A. 2 : 5
B. 3 : 5
C. 5 : 3
D. 5 : 2
Show Answer

An alloy contains zinc, copper and tin in the ratio 2 : 3 : 1 and another contains copper, tin and lead in the ratio 5 : 4 : 3. If equal weights of both alloys are melted together to form a third alloy, then the weight of lead per kg in new alloy will be:

A. $\large\frac{1}{2} \mathrm{~kg}$
B. $\large\frac{1}{8} \mathrm{~kg}$
C. $\large\frac{3}{14} \mathrm{~kg}$
D. $\large\frac{7}{9} \mathrm{~kg}$
Show Answer

In a 729 litres mixture of milk and water, the ratio of milk to water is 7 : 2. to get a new mixture containing milk and water in the ratio 7 : 3, the amount of water to be added is:

A. 81 litres
B. 71 litres
C. 56 litres
D. 50 litres
Show Answer

In what ratio must a mixture of 30% alcohol strength be mixed with that of 50% alcohol strength so as to get a mixture of 45% alcohol strength?

A. 1 : 2
B. 1 : 3
C. 2 : 1
D. 3 : 1
Show Answer



More Related Questions On Alligation