Real GMAT questions

[gmat_nidhesh]

Q1 If it is 6:27 in the eveninig on a certsin day, what time in the morning was it exactly 2,88071 7 min. earlier ? (Assume standard time in one location)

A) 6:22

B) 6:24

C) 6:27

D) 6:30

E) 6:32

 

Q2 A certain hotel has 1400 single rooms and 420 double rooms.Each room is cleaed by one person. If one person can clean a single room in every 15 min. and a double room in 20 min. How many cleaning persons are required to clean all the rooms if each person works for exactly 7 hours ?

 

A) 75

B) 70

C) 80

D) 90

E) 265

 

Q3 at a certain instant in timr the number of cars,N,travelling on a portion of a certain highway can be

 

N = (260Ld)/(600 + S^2)

 

where , L = No. of the lanes in the same direction

d= lenght of the portion of the highway in feet

s = avg. speed of the cars in miles per hour.

Based on the formula what is the estimated no. of cars travelling on a 1/2 mile portion of the highway if the highway has 2 lanes in the same direction and the average speed of the cars is 40 mph? (5280 feet = 1 mile)

A) 155

B) 96

C) 80

D) 48

E) 24

:hmm:

 

 

 

Spoiler : Q1 - C ,Q2 - B , Q3-D

 

 

[vineejay]

Q3 at a certain instant in timr the number of cars,N,travelling on a portion of a certain highway can be

 

N = (260Ld)/(600 + S^2)

 

where , L = No. of the lanes in the same direction

d= lenght of the portion of the highway in feet

s = avg. speed of the cars in miles per hour.

Based on the formula what is the estimated no. of cars travelling on a 1/2 mile portion of the highway if the highway has 2 lanes in the same direction and the average speed of the cars is 40 mph? (5280 feet = 1 mile)

A) 155

B) 96

C) 80

D) 48

E) 24

 

 

When we substitute the values:

 

N= (260 * 2 * 2640 )/ (600 + 1600), the answer does not come out to be the same

[jagan1k]

for Q1 (correct me if i am wrong)

2880717 min= 4811 hrs and 57 min

4811 hrs= 200 days and 11hrs

so the exact time is 11 hrs and 57 min before the evening

that is 6:24

 

for Q2

total hrs of work= 1400*15/60+420*20/60=490 hrs

since each worker works for only 7 hrs, total number of workers=490/7=70

 

for Q3

not sure, can anyone help?

[swethapv]

IMO B for the second one.

I agree with vineejay, about the 3rd one.

Q1 has already been discussed separately.

[synfist]

Q1 If it is 6:27 in the eveninig on a certsin day, what time in the morning was it exactly 2,88071 7 min. earlier ? (Assume standard time in one location)

A) 6:22

B) 6:24

C) 6:27

D) 6:30

E) 6:32

 

1 day = 1440 minutes ( 24 * 60 :2cents: )

2880717 = X days and 717 minutes

720 minutes = 12 hours

 

12 hours ago it was exactly same time but in the morning, that is 6.27 AM

 

so 3 minutes later it was 6.30 AM

 

Answer D :hmm:

[cartera]

In Q3 I get the following:

 

(260*2*2640)/(600+1600)=624 cars

 

Where am I wrong?

[NishantG]

I think answer for question 1 is D

it is 6:30

 

2880717 min= 4811 hrs and 57 min

4811 hrs= 200 days and 11hrs

 

Now if you subtract 11 hours 57 minutes from 6:27 PM answer comes to 6:30 minutes in the morning and not 6:24 or 6:27

[NishantG]

I am getting 624 for question 3

[synfist]

I am getting 624 for question 3

 

Me too ,

 

Its simple substitution in the formula . What could go wrong here ? :rolleyes:

 

BTW for 1 , I'm also getting D .

[jagan1k]

for Q3,i am getting 624 too but the answer is not in the five options

[cartera]

Q2.

 

15min*4*7=28 -------> 1400/28 = 50

20min*3*7=21--------> 420/21 = 20

 

50+20=70

[vinhan]

the first question has been solved by me earlier. however,

2880717 min after 6:27 p.m. would be 6:24 a.m.

because there are 1440 min. in 1 day

2880717/1440 gives 2 717/1440.

717 min is 3 minutes less than 720 min. i.e., 12 hours

the new time is 6.24 a.m.

[vinhan]

For Q2

the total no. of hrs required to clean single rooms = 1400/4 = 350

the total no. of hrs required to clean double rooms = 420/3 = 140

total no. of hrs = 490

if each person works for 7 hrs

70 persons are required

hence answer is B

[synfist]

Q1 If it is 6:27 in the eveninig on a certsin day, what time in the morning was it exactly 2,88071 7 min. earlier ? (Assume standard time in one location)

A) 6:22

B) 6:24

C) 6:27

D) 6:30

E) 6:32

 

 

the first question has been solved by me earlier. however,

2880717 min after 6:27 p.m. would be 6:24 a.m.

because there are 1440 min. in 1 day

2880717/1440 gives 2 717/1440.

717 min is 3 minutes less than 720 min. i.e., 12 hours

the new time is 6.24 a.m.

 

 

I guess we need to calculate time in the past , not in the future .

 

2,88071 7 = X days + 11 hours and 57 minutes !

 

11 hours and 57 minutes in the past is Current time + 3 minutes

11 hours and 57 minutes in the future is Current time - 3 minutes

 

Am i missing something ? :rolleyes: