In 10 years, Sergio will be as old as Carolyn is now. Thirty years ago

Question

Tough and Tricky questions: Word Problems.

In 10 years, Sergio will be as old as Carolyn is now. Thirty years ago Carolyn was twice as old as Sergio was. How old is Sergio now, in years?

A. 20
B. 24
C. 32
D. 35
E. 40

Kudos for a correct  solution .

littlewarthog · Answer

C = S + 10
C - 30 = 2 * (S - 30)

We can substitute C in the second equation with the first:

S + 10 - 30 = 2 * (S - 30)
=> S = 40

Answer E

g106 · Answer

Sergio Age now = S
Carolin S Age now = C

10 years from now C = S+10 --- (1)

30 Years before (C-30) = 2 (S-30)
 C = 2S-30 --(2)

(2) - (1) 0 = S - 40
 S = 40

Age of Sergio is 40

Ans E

Temurkhon · Answer

Eliminate A and B because age cannot be negative (after subtracting 30)

start from C

Ser: now - 32, 30 years ago - 2, in 10 years -  42

Car: now- 34 , 30 years ago - 4, in 10 years - 44 (eliminate C)

go D

Ser: now - 35, 30 years ago - 5, in 10 years -  45

Car: now -  40 , 30 years ago - 10, in 10 years - 50 (eliminate D)

it is E

qw1981 · Answer

let sergio's age be S and Carolyn age be C.

Now 10 years from now S will be equal to Carolyn's present age. Hence S+10 =C

30 years earlier Carolyn was twice as old as sergio

hence C-30=2 (s-30) ==> Substituting C=S+10 in this we get

S+10-30 = 2s-60 =>s=40.. hence answer is E.

PareshGmat · Answer

Answer = E. 40

.......................... Sergio ................... Carolyn

Current age ........... x ........................... x+10

30 yrs before ......... x-30 ........................ x-20

Given that 2(x-30) = x-20

x = 40

Bunuel · Answer

OFFICIAL SOLUTION:

(E) Let S = Sergio's current age and C = Carolyn's current age.

First, rewrite the two statements in algebraic form.

The first statement translates into:
S + 10 = C.

The second statement translates into:
C – 30 = 2(S – 30).

Because we now have two equations, we can solve for either of the variables. Substitute S + 10 in the first equation for C in the second, and solve:
(S + 10) – 30 = 2(S – 30)
S – 20 = 2S – 60,
S + 40 = 2S
S = 40.

The correct answer is choice (E).

Mo2men · Answer

organizing thoughts is key

Now

Sergio age = S
Carolyn = C

After 10 years

Sergio age = S+ 10
Carolyn = C+10

Before 30 years

Sergio age = S - 30
Carolyn = C - 30

Setting up equation:

S +10 = C.....................1

C -30 = 2 (S -30)...........2

From 1 in 2

S + 10 -30 = 2S -60

S = 40

Answer: E

Paras96 · Answer

In 10 years, Sergio will be as old as Carolyn is now. Thirty years ago Carolyn was twice as old as Sergio was. How old is Sergio now, in years?

Thirty years ago, age of Sergio = x
Then, the age of Carolyn = 2x

10 years ahead, age of Sergio = x + 40
the age of Carolyn = 2x + 40

Presently, age of Sergio = x + 30
the age of Carolyn = 2x + 30

However, it is given that => x + 40 = 2x + 30
=> x = 10

Age of Sergio now = x+30 = 40

Hence E

In 10 years, Sergio will be as old as Carolyn is now. Thirty years ago

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GMAT Problem Solving (PS) Questions

In 10 years, Sergio will be as old as Carolyn is now. Thirty years ago

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards