Data Sufficiency

. If Jack’s and Kate’s annual salaried in 1985 were each 10 percent higher than their respective annual salaries in 1984, what was Jack’s annual salary in 1984?
(1) The sum of Jack’s and Kate’s annual salaries in 1984 was $50,000.
(2) The sum of Jack’s and Kate’s annual salaries in 1985 was $55,000.


what's wrong with this solution :

j1+k1 = 50000
j2+k2=55000
j2 = 11/10 j1 and k2 = 11/10 k1 (from the question stem)

So combining 1 and 2 -> two equations, two unknowns - sufficient.


The OA is E - can someone please explain ?

When you will solve both equations both will give same result.
Both are saying same thing and 2 variables still remain 2 variables.
You cannot solve for them
IMO E

Stmt I will give j1+k1=50000

INSUFF

Stmt II will GIVE U 1.1J1+1.1KI=55000

TAKE 1.1 COMMON FACTOR OUT

1.1 (J1+K1) = 55000

J1+K1 = 50000 (55000/1.1 = 50000)

End up wiht the same eqn as stmt I

INSUFF

put together still INSUFF

E)

Let us know if u still hv questions

This is what happens when I don't solve completely. Just looked at 2 equations and 2 unknowns bang !!! .. Thanks guys.

-pradeep

This is what happens when I don't solve completely. Just looked at 2 equations and 2 unknowns bang !!!

pbanavara,

Been there done that. You are not the only one; this GMAC trick gets many of us...

Good luck!

An ancient trap that still catches many of us. WATCH OUT!

Also remember one equation 2 variables doesnt always mean its choice E). Most situations this may be the case but not always though (fine difference which we may need to spot)

Look up this problem posted by Logitech and u will see why.

https://www.beatthegmat.com/logitech-ds2-t22368.html