Final answer:
By solving two equations representing purchases of bags of sand and pea gravel, we find the price per bag of sand (X) to be $3 and the price per bag of pea gravel (Y) to be $4.
Step-by-step explanation:
The question presents two linear equations based on purchases made. From the given information, the two equations representative of the purchases are:
1) 4X + 3Y = $24 (First purchase of sand and pea gravel)
2) 2X = $6 (Second purchase of just sand).
Solving the second equation directly gives the price of one bag of sand:
X = $6 / 2
X = $3
We substitute the value of X into the first equation to find Y:
4($3) + 3Y = $24
$12 + 3Y = $24
3Y = $24 - $12
3Y = $12
Y = $12 / 3
Y = $4
Therefore, the price per bag of sand (X) is $3, and the price per bag of pea gravel (Y) is $4, which corresponds to option a).