Question

Lucy spends $140 at the grocery store. Dairy items made up 1/7 of her purchase and vegetables accounted for 3/20 of her total. How much money did Lucy spend on items that were not dairy or vegetable items?

Answer 1

For this case we make a rule of three to find the cost of dairy products and vegetables.

$ 140 --------------> 1

x ------------------>
`\frac {1} {7}`

Where "x" represents the amount of money spent on dairy products.

`x = \frac {\frac {1} {7} * 140} {1}\\x = 20`

So, I spend $ 20 on dairy products.

Now we have:

$ 140 --------------> 1

y ------------------>
`\frac {3} {20}`

Where "y" represents the amount of money spent on vegetables.

`x = \frac {\frac {3} {20} * 140} {1}\\x = 21`

So, I spend $ 21 on vegetables.

Therefore, I spend $ 41 on vegetables and dairy products.

$ 140- $ 41 = $ 99

Spending $ 99 dollars on products other than vegetables and dairy products

Answer

$ 99