At a local plant sale, janice was selling golden barrel cactus plants and baby saguaros. during the sale, she sold 5 times as many saguaros ($6 each) as golden barrels ($10 each). she made a total of $720 during the plant sale. how many saguaros did janice sell? . a.. 18. b.. 40. c.. 72. d.. 90.

Let x be the number of Golden Barrel Cactus Janice sold. By the representation, the number of Saguaros she sold was 5x. The total earnings she had from her goods were 6(5x) for Saguaros and 10x for Golden Barrel. With her total earning reaching up to $720, the equation becomes
                                30x + 10x + 720     ; x = 18
18 is the number of Golden Barrel she sold and five times this number is the number of Saguaros. Thus, she sold 90 pieces of Saguaros. 

The answer is D. 90 Saguaros.

Solution:
Let x= number of Golden Barrel Cactus plants ; y= number of baby Saguaros

sold 5 times as many Saguaros as Golden Barrels: y= 5x

total of 720 dollars during plant sale: 6y +10y = 720

Solving for x and y as two linear equations with two unknowns or by substitution method we get:
x= 18
y= 90