Question

Molly and Arthur are taking their daughter Ginny on a roller coaster ride. For safety, they need to find their total weight before getting into the same car. Molly’s weight is MMM kilograms, Arthur’s weight is AAA kilograms, and Ginny’s weight is GGG kilograms.

The expression (M+A)+G(M+A)+Gleft parenthesis, M, plus, A, right parenthesis, plus, G describes their total weight. We can also use the expression A+(G+M)A+(G+M)A, plus, left parenthesis, G, plus, M, right parenthesis to represent the same quantity.

Match each amount in the situation with the expression that represents it.

For reference:

Molly is a female and an adult.

Arthur is a male and an adult.

Ginny is a female and a child.

Answer 1

A

G+M

G

M+A

Explanation:

Answer 2

This is weirdly written, but let's try to solve it:

M is the mass of Molly

A is the mass of Arthur

G is the mass of Ginny.

We can represent the weight as:

(M + A) + G

or as:

A + (G + M)

the first situation shows that Molly and Arthur are weight together (this is why their weight is shown as only one), and then they weight Ginny alone.

The second situation shows that Arthur is weight alone, and Ginny and Molly are weight together (this is why their weight is written as only one)