P and Q are two alloys of aluminium and copper. The ratios of aluminium and copper in P and Q are 5: 11 and 3: 5, respectively. If a third alloy is formed by mixing alloys P and Q in the ratio of 1: 3, then aluminium is what percentage (rounded off to the nearest integer) of the copper in the third alloy ?

56 Percent

Ratio in P;

Al : Cu = 5 : 11 =  (5 + 11) = 16 units,

Ratio in Q,

Al : Cu = 3 : 5 = (3 + 5) = 8 units,

To make unit equal we multiply Q with 2,

Therefore new ratio of Q,

Al : Cu = 6 : 10,

⇒ Now the third Alloy is formed by mixing P and Q in ratio 1 : 3.

Now multiplying P ratio with 1 and Q with 2,

So, Final ratio of third alloy = Al : Cu = 23 : 41,

Required percentage = \(\frac{23}{41}\) x 100 = 56.09 = 56%