Question

In 2013, an 11-inch Apple MacBook Air weighed about 13.6 lb less than the Apple Macintosh Portable did in 1989. If the two computers weighed a total of 18.4 lb, what was the weight of the Apple Macintosh Portable in 1989?

A) 4.8 lb
B) 13.6 lb
C) 18.4 lb
D) 31.6 lb

Answer 1

The weight of the Apple Macintosh Portable in 1989 was 16 lb, as calculated by setting up and solving a simple algebraic equation, given that the total weight of it and the 11-inch MacBook Air from 2013 was 18.4 lb with the MacBook Air weighing 13.6 lb less than the Macintosh Portable.

Step-by-step explanation:

To find the weight of the Apple Macintosh Portable in 1989, we need to set up a simple algebraic equation. Let x be the weight of the Macintosh Portable and x - 13.6 lb be the weight of the 11-inch Apple MacBook Air in 2013. Given that the two computers together weighed 18.4 lb, we can write the following equation:

x + (x - 13.6 lb) = 18.4 lb

Solving this equation by combining like terms and isolating x, we get:

2x - 13.6 lb = 18.4 lb

2x = 18.4 lb + 13.6 lb

2x = 32 lb

x = 16 lb

The weight of the Apple Macintosh Portable in 1989 was 16 lb, which makes option D) 31.6 lb incorrect, as 31.6 lb does not match the correct weight of the Macintosh Portable plus the MacBook Air. The correct answer is not listed in the options provided.