Question posted by Gazelle from Singapore:

1 table and 2 chairs cost $77.

3 tables and 1 chair cost $151.

What is the cost of 1 table and 1 chair?

Answer:

Step 1: Draw the relevant boxes to represent the 2 sets of information given in the first 2 sentences of the question.

Step 2: Reproduce another set of the model for the "3 tables and 1 chair".

(We do this to eliminate the "chair" units from the model. This leaves only the "table" units making it possible to divide the numerical value by the number of "table" units.)

Step 3: Deduct the total value of the first row of the model($77) from the total value of the second row ($302).

2 X $151 = $302

$302 - $77 = $225

The result will be the value of the 5 "table" units.

$225 / 5 = $45 (1 table)

Step 4: Find the cost of 1 chair.

$77 - $45 = $32 (2 chairs)

$32 / 2 = $16 (1 chair)

$45 + $16 = $61

Thus, the cost of 1 table and 1 chair is $61.