Can you show me the logic process in working out this problem? I fully understand all calculations, but the logic of how to work it out as proposed by Manhattan GMAT.... I don't understand.
Problem: 8 years ago, George was half as old as Sarah. Sarah is now 20 years older than George. How old will George be in 10 years?
Take George's age 8yrs ago: G-8=S-8/2 rewritten 2G - 16 = S-8
Sarah is now 20 years older than George: G + 20 = S OR G = S - 20
2G - 16 = S - 8 - [G = S - 20]
EQUALS G - 16 = 12
G = 28YRS TODAY.
G= 38YRS OLD 10 yrs from now
THIS LAST STEP I DO NOT UNDERSTAND. PLEASE EXPLAIN THE LOGIC....WHY WOULD SUBTRACT GEORGE'S AGE 8YRS AGO FROM GEORGE'S AGE TODAY TO GET 28?
Problem: 8 years ago, George was half as old as Sarah. Sarah is now 20 years older than George. How old will George be in 10 years?
Take George's age 8yrs ago: G-8=S-8/2 rewritten 2G - 16 = S-8
Sarah is now 20 years older than George: G + 20 = S OR G = S - 20
2G - 16 = S - 8 - [G = S - 20]
EQUALS G - 16 = 12
G = 28YRS TODAY.
G= 38YRS OLD 10 yrs from now
THIS LAST STEP I DO NOT UNDERSTAND. PLEASE EXPLAIN THE LOGIC....WHY WOULD SUBTRACT GEORGE'S AGE 8YRS AGO FROM GEORGE'S AGE TODAY TO GET 28?
