Alloy X is copper and tin by mass. Alloy Y is copper and tin by mass. How many kilograms of X must be melted with kg of Y to obtain an alloy that is exactly half copper and half tin?
Answer and explanation
Correct answer: C.
- Step 1: Let be the mass of Alloy X in kilograms. Total copper mass is . Total tin mass is .
- Step 2: Equate the copper and tin masses for equal proportion: .
- Step 3: Solve for : .
Answer
.
Why not the others: is the total mass of the resulting mixture (); divides by instead of ; equates with with a sign inversion or omitted term; uses an equal mass of Alloy X.
Practise more Ratios and proportions.
Free questions with an explanation for every one, and full timed GRE mock tests.
More Ratios and proportions questions
- Boys and girls in a club are in the ratio . If the club has members, how many are girls?
- Boys and girls in a club are in the ratio . If the club has members, how many are girls?
- Boys and girls in a club are in the ratio . If the club has members, how many are girls?
- Boys and girls in a club are in the ratio . If the club has members, how many are girls?
- The ratio of to is . If is added to and is subtracted from , the new ratio of to is . What is the…
- A cyclist rides the first of a trip at km/h and the remaining at km/h. What is the average speed for the whole…