Answer: Andre picked 252 pounds of apples
Step-by-step explanation:
Let x = number of pounds of apple picked by Jane.
Let y = number of pounds of apple picked by Andre
Let z = number of pounds of apple picked by Maria
Andre picks three times as many pounds as maria. It means that
y = 3z
Jane picks two times as many pounds as Andre. It means that
x = 2y
The total weight of the apples is 840 pounds. It means that
x + y + z = 840 - - - - - - - - - 1
We will substitute z = y/3 and x = 2y into equation 1
2y + y + y/3 = 840
Cross multiplying with 3
6y + 3y + y = 2520
10y = 2520
y = 2520/10 = 252
x = 2y = 252× 2 = 504
z = y/3 = 252/3 = 84