A hardware store clerk mixed nuts worth $1.32 per kilogram with bolts worth $1.20 per kilogram. If he made 108 kilograms of a mixture worth $1.22 per kilogram, how many kilograms of nuts are in the mixture?

the way to work these types of problems is to create a table. The table will have three rows and three columns.

The table:

Let x represent the kilograms of nuts, then 138 - x will represent the kilograms of bolts.

Product     Amount        Cost            Total

  Nuts          x               .60         .60 * x

  Bolts      138 - x          .66         .66 * (138 - x)

  Mix          138             .65         .65 * (138)

Step-by-step explanation:

The equation:

The nuts plus the bolts must equal the mix or:

.60 * x + .66 * (138 - x) = .65 * 138

I do not like to work with decimals, so multiply each term by 100:

60 * x + 66 * (138 - x) = 65 * 138

Remove the parenthesis and combine like terms:

-6x = -66 * 138 + 65 * 138

-6x = -138

Divide both sides by -6:

x = 23

Solution:

The mixture contains 23 kilograms of nuts.

The mixture contains 138 - 23, or 115 kilograms of bolts.

$450 is the answer.

step-by-step explanation:

30% of 450 = 135

450-135=315