Tweedledum says The sum of your weight and twice mine is 361 pounds. Tweedledee answers the sum of your weight and twice mine is 362 pounds. Find the absolute difference between the two weights?

Answer 1

Let x lb be Tweedledum's weight and y lb be Tweedledee's weight. We can write a system of linear equations:

(1) y + 2x = 361

(2) x + 2y = 362.

Let's solve this by substitution: first, rewrite equation (1) as y = 361 - 2x, then substitute for y in equation (2) ...

x + 2(361 - 2x) = 362

x + 722 - 4x = 362

-3x = 362 - 722

x = -360/-3

x = 120.

Now substitute that back into the first equation as rewritten:

y = 361 - 2(120)

y = 361 -240

y = 121.

Tweedledum weighs 120 pounds and Tweedledee weighs 121 pounds. The difference of their weights is one pound.

Answer 2

The absolute difference is 1 pound.