Four apples and six oranges weigh 61. Six apples and four oranges weigh 59 ounces. What is thee weight of one apple and one orange together.

2 answers

Three ducks and two ducklings weigh 32kg. Four ducks and three ducklings weigh 44kg. All ducks weigh the same and all ducklings weigh the same. What is the weigh of two ducks and one ducklings?
If apples weigh x and oranges weigh y, then you have
4x+6y = 61
6x+4y = 59
so, 10x+10y = 120
x+y = 12

If ducks weigh x and ducklings weigh y, then
2x+2y = 32
4x+3y = 44
subtract the top from the bottom
2x+y = 12