Problem Solving

Hey guys,

This question seems easy but from some reason I couldn't solve it...plz help

A certain phone company offers two plans A and B. Under plan A, the company charges a total of 0.6 for the first 7 min. of each call and $0.06 per minute thereafter. Under plan B the company charges $0.08 per minute of each call. what is the duration of call, in minutes, for which the company charges the same amount under plan A and under plan B?

I got this equation:
0.6*7 + (x-7)*0.06 = 0.08*x

that is probably a mistake....right?

Your equation looks great! Now you just need to solve for x....

We start with:

0.6*7 + (x-7)*0.06 = 0.08*x

Multiply out to get:

4.2 + 0.06x - 0.42 = 0.08x

Combine like terms:

3.78 = 0.02x

Multiply everything by 100:

378=2x

Divide by 2:

189 = x

So, the calls cost the same when you talk for 189 minutes.

Best wishes,

Tatiana

Thank you Tatiana... I got 189 also...
I forgot to post the answers:
A)2 B)9 C)15 D)21 E)30
and the correct answer btw is: B)9
is that weird or am I missing something?

It seems that the answer choices do not correspond to this problem. If you plug in 9 to your algebraic expression, you do not get an equality.

Best wishes,

Tatiana

read carefully the text

A certain phone company offers two plans A and B. Under plan A, the company charges a total of 0.6 for the first 7 min. of each call and $0.06 per minute thereafter...

so the equation is, in cents

60 + (t-7) * 6 =8t

answer 9

ciao

Tricky... Thank You For Enlightening Me

0.60 + 0.06 T -0.42 = .08T

T= 9

0.60 + 0.06 T -0.42 = .08T

T= 9

wowww

now thats a tricky one
i was puzzled too

tks guys

maya2008 wrote:Hey guys,

This question seems easy but from some reason I couldn't solve it...plz help

A certain phone company offers two plans A and B. Under plan A, the company charges a total of 0.6 for the first 7 min. of each call and $0.06 per minute thereafter. Under plan B the company charges $0.08 per minute of each call. what is the duration of call, in minutes, for which the company charges the same amount under plan A and under plan B?

I got this equation:
0.6*7 + (x-7)*0.06 = 0.08*x

that is probably a mistake....right?

yeah! it is.

For option a: for x mins total cost= 0.6+(x-7)*0.06 [where, x>=7]
For option b: for x mins total cost= 0.08*x

now 0.6+(x-7)*0.06=0.08*x

solve it.

This is a very very simple question

The answer is 9 min

If one reads the stimulus , one can see that plan A charges $ 0.6 of the 1st 7 min and plan B charges $0.08 per min since 0.6 is not divisible by 0.08

we know that the time is greater than 7 min

the value which is common to both plan A and Plan B is 0.72

Plan A ------> 0.6+0.06*2 =0.72 ( 9 mins )

Plan B ---------> 0.08*9 = 0.72

ghacker wrote:This is a very very simple question

The answer is 9 min

If one reads the stimulus , one can see that plan A charges $ 0.6 of the 1st 7 min and plan B charges $0.08 per min since 0.6 is not divisible by 0.08

we know that the time is greater than 7 min

the value which is common to both plan A and Plan B is 0.72

Plan A ------> 0.6+0.06*2 =0.72 ( 9 mins )

Plan B ---------> 0.08*9 = 0.72

Ghacker; it's really counter-productive to the spirit of this website to keep saying "This question is very very simple" all the time.

This question is very very simple for "you"; but for folks preparing for this test it may be disheartening to hear that.

You are a great contributor to this board; I hope you can change the tone of your posts to more encouraging than pedantic.

Sincerely,
Musiq

I agree with Musiq.

For anyone practising the GMAT to read that they could not solve "a very very simple question" is quite dissappointing.