Question

50 kg of an alloy of lead and tin contains 60% of lead. How much lead must be
melted into it to make the alloy contain 75% of lead?
​

Answer 1

Answer:

HI

GOOD AFTERNOON

Step-by-step explanation:

Quantity of lead in 50 kg of alloy = 60% of 50 kg =  kg = 30 kg.

Let the required quantity of lead to be added be x kg.

Then, weight of lead = (30 + x) kg.

And, weight of new alloy = (50 + x) kg.

Percentage of lead in new alloy =  %

∴

⇒

⇒

⇒ 4(30 + x) = 3(50 + x)

⇒ 120 + 4x = 150 + 3x

⇒ 4x - 3x = 150 - 120

⇒ x = 30

TQ

Answer 2

Answer:

for lead to be 75% it should be .75×50=37.5kg

already leaf present=.6×50=30kg

so 37.5-30=7.5kg more lead is to melted