Question

The gardening store sells clay flower pots, which hold 2 litres of dirt, and ceramic flower pots, which hold 7 litres. Tara bought 35 flower pots, which will hold a total of 150 litres of dirt. How many of each flower pot did she buy?

Answer 1

The number of clay flower pots = 19

The number of ceramic flower pots = 16

Explanation:

Answer 2

The number of clay flower pots = x = 19

The number of ceramic flower pots = y = 16

Explanation:

Let

The number of clay flower pots = x

The number of ceramic flower pots = y

Tara bought 35 flower pots

= x + y = 35

x = 35 - y

The gardening store sells clay flower pots, which hold 2 litres of dirt, and ceramic flower pots, which hold 7 litres. Tara bought 35 flower pots, which will hold a total of 150 litres of dirt.

Hence:

2x + 7y = 150.... Equation 2

Substitute 35 - y for x in Equation 2

2 (35 - y) + 7y = 150

70 - 2y + 7y = 150

-2y + 7y = 150 - 70

5y = 80

y = 80/5

y = 16 flower pots

x = 35 - y

x = 35 - 16

x = 19 flower pots

The number of clay flower pots = x = 19

The number of ceramic flower pots = y = 16