In the last week, Todd has lost 12 pounds and now weighs exactly three times as much as his younger brother...

BTGmoderatorLU wrote: ↑

Mon Oct 19, 2020 4:49 pm

Source: Veritas Prep

In the last week, Todd has lost 12 pounds and now weighs exactly three times as much as his younger brother. Together they weigh 280 pounds. How much did Todd weigh a week ago, in pounds?

A. 210
B. 213
C. 220
D. 222
E. 225

The OA is D

Solution:

We can let t = Todd’s old weight and b = his brother’s current weight.

We can create the following equations:

t - 12 = 3b

And

t - 12 + b = 280

Replacing t - 12 in the second equation by 3b, we have:

3b + b = 280

4b = 280

b = 70

Substitute b = 70 back into the very first equation, we have:

t - 12 = 3(70)

t = 222

Alternate Solution:

Let’s let x = brother’s current weight. This means that Todd’s current weight = 3x. We have:

x + 3x = 280

4x = 280

x = 70

Todd’s brother weighs 70 pounds, and Todd currently weighs (3)(70) = 210 pounds. Last week Todd weighed 12 more pounds, so last week he weighed 222 pounds.

Answer: D