Peter works as a teaching assistant and gets paid on a weekly basis.

Question

GMATBusters’ Quant Quiz Question -7

For past quiz questions, click  here

Peter works as a teaching assistant and gets paid on a weekly basis. He gets paid D dollars per hour for the first 30 hours and (D+ 10) dollars per hour for the hours worked in excess of 30 hours. What is the value of D?
(1) Last week Peter worked for 32 hours.
(2) Peter got paid $8(D+10) more if worked for 40 hours instead of 32 hours.

(1) Last week Peter worked for 32 hours.
(2) Peter got paid $8(D+10) more if worked for 40 hours instead of 32 hours.

Raxit85 · Answer

Suppose, peter’s wage for first 30 hours = $D per hour
Number of hours that Peter worked in excess of 30 hours = x
Peter’s wage for the extra hours = x (D+10)
Peters total wage if he works over 30 hours = 30D + x (D+10)
(1) Last week Peter worked for 32 hours.
No: of hours Peter worked in excess = x = 32- 30 =2
But this does not help us in finding value of D
So, insufficient.
 (2) Peter got paid $8(D+10) more if worked for 40 hours instead of 32 hours
If Peter worked for 32 hours, x = 2
Peter’s pay = 30D + 2 (D+10)
If Peter worked for 40 hours, x = 10
Peter’s pay = 30D + 10 (D+10)
As we can see that difference is = 30D + 10(D+10) -30D – 2(D+ 10) = 8D + 100
So no new info and insufficient
1) + 2) 
Even after combining both the statement, we cannot find the value of D.
Imo. E

ashwini2k6jha · Answer

Answer:E
D=?
State:1 not sufficient
Total payment of 32 hour= 30xD+(D+10)x(32-30)=32D+20
No information given about total payment
State :2 not sufficient
Given 8X(D+10)=payment for 40 hours- payment for 32 hours= - 
8(D+10)=8(D+10) NOT SUFFICEINT
Combining 1 &2,no new information,hence not sufficient

uc26 · Answer

Let T be the total number of hours Peter worked.
For the first 30 hours, peter gets paid D dollars per hour which means 30D.
For every hour in excess of 30, he gets paid (D+10) per hour which means he earns (T-30)(D+10).
Total amount earned= 30D+ (T-30)(D+10)

1) We don't know how much he earned by working for 32 hours. Not sufficient to find D.
2) We can get a linear equation in D. Sufficient.

Answer: B

yashikaaggarwal · Answer

IMO E

Statement 1: Peter worked for 32 hours. 
His income = 30D+(D+10)+(D+10) for 32 hours, D till 30 and D+10 for each extra hour.
Total income for 32 hours = 30D+2D+20 = 32D+20 
No constraint to drive D value.
(Insufficient)

Statement 2: if Peter had worked for 40 hours instead of 32hours. he had earned 8(D+10)$ more
Peter earning for 40 hours - earning for 32 hours = 8(D+10)
30D+10D+100-30D-2D-20 = 8(D+10)
8D+80 = 8(D+10)
O=0 
No constraint to drive D value.
(Insufficient)

Posted from my mobile device

Archit3110 · Answer

Peter weekly salary ; 
paid D dollars per hour for the first 30 hours and (D+ 10) dollars per hour for the hours worked in excess of 30 hours
D*30+(D+10)*(X-30) WHERE X >30 HOURS 
#1
Last week Peter worked for 32 hours.
30D+(D+10)*2
32D+20
VALUE OF D IS NOT KNOW INSUFFICIENT
#2
Peter got paid $8(D+10) more if worked for 40 hours instead of 32 hours.
SALARY OF 40 HOURS - SALARY OF 32 HOURS = $8(D+10)
(30D+10D+100)-(32D+20) = 8D+80
40D+100-32D-20=8D+80
8D+80=8D+80
VALUE OF D CAN BE 1,2,3... UNKNOW INSUFFICIENT
FROM 1&2 NOTHING CAN BE DETERMINED
OPTION E

Peter works as a teaching assistant and gets paid on a weekly basis. He gets paid D dollars per hour for the first 30 hours and (D+ 10) dollars per hour for the hours worked in excess of 30 hours. What is the value of D?
(1) Last week Peter worked for 32 hours.
(2) Peter got paid $8(D+10) more if worked for 40 hours instead of 32 hours.

Gamerboyttt · Answer

E. 
Neither statement is enough

Posted from my mobile device

SohGMAT2020 · Answer

Peter works as a teaching assistant and gets paid on a weekly basis. He gets paid D dollars per hour for the first 30 hours and (D+ 10) dollars per hour for the hours worked in excess of 30 hours. What is the value of D?
(1) Last week Peter worked for 32 hours.
(2) Peter got paid $8(D+10) more if worked for 40 hours instead of 32 hours.

Solution:

1. For 32 hours, he will get 30D + (D+10)*2 = 32D +20 dollars. However, nothing else is given hence D cannot be determined.  Insufficient.

2. For 40 hours, he will get 30D + (D+10)*10 = $8(D+10) more than 32D +20 dollars. However, nothing else is given hence D cannot be determined.  Insufficient
 
Combining them is also no good.
 
So, 1 and 2 together are not sufficient, Hence Option E is correct

tejas29d · Answer

statement 1 and 2 both are insufficient as 
1. 32 hours worked provides no value for D
2. 8 (d+10) also gives no value of d

Kinshook · Answer

Given: 
1. Peter works as a teaching assistant and gets paid on a weekly basis. 
2. He gets paid D dollars per hour for the first 30 hours and (D+ 10) dollars per hour for the hours worked in excess of 30 hours.

Asked: What is the value of D?

(1) Last week Peter worked for 32 hours.
Peter gets paid = 30D + 2(D+10) = $(32D + 20)
Value of D can not be derived.
NOT SUFFICIENT

(2) Peter got paid $8(D+10) more if worked for 40 hours instead of 32 hours. 
Peter gets paid for 32 hours = 30D + 2(D+10) = $ (32D + 20)
Peter gets paid for 40 hours = 30D + 10(D+10) = $ (40D + 100)
Difference = 8D + 80 = $8(D+10)
The statement does not provide any additional information, value of D can not be derived.
NOT SUFFICIENT

(1) + (2) 
(1) Last week Peter worked for 32 hours.
Peter gets paid = 30D + 2(D+10) = $(32D + 20)
(2) Peter got paid $8(D+10) more if worked for 40 hours instead of 32 hours. 
Peter gets paid for 32 hours = 30D + 2(D+10) = $ (32D + 20)
Peter gets paid for 40 hours = 30D + 10(D+10) = $ (40D + 100)
Difference = 8D + 80 = $8(D+10)
Since both statements do not provide any information about D.
NOT SUFFICIENT

IMO E

HoneyLemon · Answer

E ,  imo

Peter works as a teaching assistant and gets paid on a weekly basis. He gets paid D dollars per hour for the first 30 hours and (D+ 10) dollars per hour for the hours worked in excess of 30 hours. What is the value of D?
(1) Last week Peter worked for 32 hours.
(2) Peter got paid $8(D+10) more if worked for 40 hours instead of 32 hours.

If n is the total hours worked by peter . 
total payment = 30D + (n-30) (D+10)
(1) Last week Peter worked for 32 hours.
Total payment = 30D + 2(D +10) -- no info about total payment . so Cannt get D . insufficient

(2) Peter got paid $8(D+10) more if worked for 40 hours instead of 32 hours.
If T is the total payment 
T + 8(D+10 )= 30D + 10 (D+10 )
T = 30 + 2 (D+10 ).. 
still we cannot say about D . so Insufficient .

Combining both we cannot get the ans as well.

Hence E .

coreyander · Answer

Lets first form a general equation for the question stem.
Let T be the total hours worked by Peter... (Lucky if he works and gets paid during the Lockdown)
Let A be the total amount earned by him.

herefore A = 30*D + (T-30)*(D+10) 
 D=?

(1) Last week Peter worked for 32 hours. 
T=32

So  A = 30D + 2*(D+10)

If information about A is given, we can find D. But A isn't given...... (maybe coz he dint get paid?) 
 Thus, (A) is insufficient.

(2) Peter got paid $8(D+10) more if worked for 40 hours instead of 32 hours.

Amount he gets for 40 hours, then  T1 = 30*D + 10(D+10) 
Amount he gets for 32 hours, then  T2 = 30*D + 2(D+10)

The statment gives us the value of the difference between  T1-T2=8(D+10) 
30*D + 10(D+10) - {30D + 2(D+10)} = 8(D+10)
8(D+10)=8(D+10).

All the values will cancel out. 
 Thus, (B) is insufficient...  (Had the difference been given only as Dollars, We could find the value of D. But he dint get paid, did he?)

Combining A & B, we dont have any new information that we'd use, thus answer is (E) Both statements are insufficient.

bumpbot · Answer

Automated notice from GMAT Club BumpBot: 

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

 This post was generated automatically.

Peter works as a teaching assistant and gets paid on a weekly basis.

Prep Toolkit

Top 5 GMAT Debrief Videos

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

GMAT Data Sufficiency (DS) Questions

Peter works as a teaching assistant and gets paid on a weekly basis.

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