Question

Two cubes of bronze have a total weight equivalent to 60 kg. The first piece contains 10 kg of pure zinc and the second piece contains 8 kg of pure zinc. What is the percentage of zinc in the first piece of bronze if the second piece contains 15 percent more zinc than the first?

Options

• 15%

• 25%

• 55%

• 24%

Answer 1

25%

Explanation:

Let the first and the second piece of bronze be = x kg, (60 − x)kg

ATQ

`8/(60-"x")-10/"x"=15/100`

`(8"x"-600+10"x")/("x"(60-"x"))=3/20`

3x² + 180x − 12000 = 0

`"x"=40%=10/40xx100=2.5%`