Question 150 Problem Solving 2018 GMAT Official Guide Video explanation: If Jake loses 8 pounds, he will weigh twice as much as his sister…

Alejandro says January 30, 2022 at 8:50 AM when you have the two equations it’s much simpler to deduct one from the other one and you get 3S=270, S=90. Then replace 278 – 90 gives you 188, E Reply

GMAT Quantum says April 25, 2022 at 1:14 PM Absolutely right. In this case, solving for $S$ first is arithmetically faster, although not by a huge margin to make a big difference. In general, I will solve for the variable that is listed in the question. Reply

Alejandro says

when you have the two equations it’s much simpler to deduct one from the other one and you get 3S=270, S=90. Then replace 278 – 90 gives you 188, E

GMAT Quantum says

Absolutely right. In this case, solving for $S$ first is arithmetically faster, although not by a huge margin to make a big difference. In general, I will solve for the variable that is listed in the question.