In an alloy, the ratio of copper and zinc is 5 : 2. If 1.250 kg of zinc is mixed in 17 kg 500 gm of alloy, then the ratio of copper and zinc will be = ?

Solution(By Examveda Team)

The ratio of copper and zinc is 5 : 2
i.e 5x : 2x
Quantity of initial mixture = 17.5 kg
∴ 5x + 2x = $$\frac{35}{2}$$
⇒ x = $$\frac{5}{2}$$
Quantity of Copper in initial mixture
$$\eqalign{ & = \frac{5}{2} \times 5 \cr & = \frac{{25}}{2}kg \cr} $$
Quantity of Zinc in initial mixture
$$\eqalign{ & = \frac{5}{2} \times 2 \cr & = 5\,kg \cr} $$
Now after adding 1.250 kg of zinc
= 5 + 1.250
= 6.250 kg
= $$\frac{{25}}{4}kg$$
∴ New Ratio of copper : zinc
$$\eqalign{ & = \frac{{25}}{2}:\frac{{25}}{4} \cr & = 2:1 \cr} $$