On January 1, Ashutosh opened a current account by investing $300. On

Question

On January 1, Ashutosh opened a current account by investing $300. On each of 8th January and 15th January, he invested $n on that account. However, on 22nd January he withdrew $250 from the account due to an emergency need. If the balance on that account at the end of 31st January was $300, and the average balance for each day was also $300, then what is the approximate value of n?

A. 43
B. 55
C. 61
D. 72
E. 97

A. 43
B. 55
C. 61
D. 72
E. 97

lifeforhuskar · Answer

cannot understand the question, can someone explain

rishab0507 · Answer

Answer C : 
I did it by putting in values : as this is also one of ways tutorials suggests , Started with Option C and checked Option D,
let values be on 1st, 8,15,22, and 31 be : 300, 361, 423,173 
multiplying by no .of days they were in account : (300*7 +361*7+423*7 + 173*9)/ 31 (no. of days) =295
on checking option D it comes 312, So 61 is more closer and approx value :

Archit3110 · Answer

given 1st Jan 300$
8th and 15th Jan ; n$+n$; 2n$
upto 20th ; 300+2n 
21st ; 300+2n-250 ; 50+2n $
so avg
(50+2n)*31/31 = 300 
solve for n =125
~ for two days 125/2 ; 61 IMO C

On January 1, Ashutosh opened a current account by investing $300. On each of 8th January and 15th January, he invested $n on that account. However, on 22nd January he withdrew $250 from the account due to an emergency need. If the balance on that account at the end of 31st January was $300, and the average balance for each day was also $300, then what is the approximate value of n?

A. 43
B. 55
C. 61
D. 72
E. 97

A. 43
B. 55
C. 61
D. 72
E. 97

santorasantu · Answer

IMO answer is B

average = 300 = (300*7+(300+n)*7+(300+n+n)*7+(300+n+n-250)*9+300)/31, solving this we get n as approx 297
so imo answer is B

kitipriyanka · Answer

Assuming each day he is getting some minor interest of $x. As we need to find approximate value , so taking interest of each day as constant
Jan1=300
Jan8=300+n+7x
Jan15=300+2n+14x
Jan22=50+2n+21x
Jan31=300=50+2n+30x

Now resolving, 300=50+2n+30x
2n+3x=250
n=125.5- \frac{3}{2} x

In order to keep x as minimum from all the provided options
n=97 gives the minimum value of x
Hence E

sanpreetsingh · Answer

for 1-7 --> 7 days --> amount --> 300
8-14 --> 7 days --> amount(300+n)
15-21 --> 7 days --> amount(300+2n)
22-31 --> 10 days --> amount(300-250+2n)

The equation would be 
 /31 = 31(300)

Solving the equation gives approx n = 61.

Hence, C is the answer.

Mizar18 · Answer

On January 1, Ashutosh opened a current account by investing $300. On each of 8th January and 15th January, he invested $n on that account. However, on 22nd January he withdrew $250 from the account due to an emergency n

Sayon · Answer

*7 +  7 +  7 +  10 = 9300

=> n = 61 (approx)

Answer C

exc4libur · Answer

Given: average of 31 days is 300

Sum of daily balance in the periods
1-7th: 7(300)
8-14th: 7(300+n)
15-21th: 7(300+2n)
22-30th: 9(300-250+2n=50+2n)
31st: 300
Total: 7050+39n

Average=Sum•N…300=(7050+39n)/31…31*300=(7050+39n)…n=(9300-7050)/39=2250/39=aprox.57 or 55.

Answer (B).

dvishal387 · Answer

We can create an equation as we read the question -
300*7 +(300+n)*7+(300+2n)*7+(300+2n-250)*10=31*300
=>41n+9300-2500=9300
=>n=2500/41
~61
IMO C is the correct choice.

kavach · Answer

On January 1, Ashutosh opened a current account by investing $300. On each of 8th January and 15th January, he invested $n on that account. However, on 22nd January he withdrew $250 from the account due to an emergency need. If the balance on that account at the end of 31st January was $300, and the average balance for each day was also $300, then what is the approximate value of n?

A. 43
B. 55
C. 61
D. 72
E. 97

A. 43
B. 55
C. 61
D. 72
E. 97

Simple question.

Starting Balance = $300
8th Jan = 300+ N 
15th Jan = 300+ N + N 
22nd Jan = 300+N+N-250 
31st Jan = 300

Lets put a simple equation: 300+ 2N - 250 = 300 
N = 125 .

Seeing the answer choices 61*2 = 122 Approximately 125

Hence the answer is C.

Prasannathawait · Answer

i guessed it and marked 55.
don't know how to approach

Posted from my mobile device

Anand0802 · Answer

Avg for 31 days is 300 so total=300*31=9100
So we can divide this in 4 dates
1st Jan to 7th Jan ->7 days
300*7=2100
8th to 14th Jan ->7 days
(300+n)*7=2100+7n
15th to 21st jan-> 7 days
(300+2n)*7=2100+14n
Remaining 10 days from 22nd to 31st=(300-250+2n)*10=500+20n
So,
2100+2100+7n+2100+14n+500+20n=9300
=>41n=9300-6800=>n=~61

Posted from my mobile device

techloverforever · Answer

Option C

MahmoudFawzy · Answer

in 1st 7 days, the balance was 300 --> sum = 2100
in 2nd 7 days, the balance was (300+n) --> sum = 2100 + 7n
in 3rd 7 days, the balance was (300+2n) --> sum = 2100 + 14n
in last 10 days, the balance was (50+2n) --> sum = 500 + 20n

the average of the 31 days =  \frac{{6800+41n}}{31} = 300 
so  41n = 2500 ,  n ≃ 61    C

gmatenthureturns · Answer

C I think.

We need to get monthly average based on transaction across the month.

So, we get: 7*300+8*(300+n) + 6*(300+2n)+10*(50+2n) = 31*300
Solve for n, we get n = 62.5

Lampard42 · Answer

the average balance for each day was also $300, Hence - 31*300(Sum of all day balances)= 7*300<first 7 days>+7*300+7n <2nd 7 days> + 7*300+7*2n <3rd 7 days> + 10*50 + 10*2n <For balance 10 days, after 250 withdrawal>

9300=2100+2100+7n+2100+14n+500+20n
3000=500+41n
41n=2500
n=2500/41~2500/40=62.something

IMO C = 61 (Less than 62 as denominator was reduced in the above calculation)

Staphyk · Answer

On January 1 , Ashutosh opened a current account by investing  $300 . On each of  8th January and 15th January , he invested  $n  on that account. However, on  22nd January  he withdrew $250 from the account due to an emergency need. If the balance on that account at the  end of 31st January was $300 , and the average balance for each day was also $300, then what is the approximate value of n?

Since the balance at the end of 31st Jan is the same as his initial deposit of $300
The two $n is equal to the withdrawal amount 
.: 2n = 250 —> n= 125
Now we also know that averagely he deposits $300
.: approximate value of n has to be a multiple of 5
From answer choice only answer B is a multiple of 5

.: Answer B

Posted from my mobile device

Kinshook · Answer

On January 1, Ashutosh opened a current account by investing $300. On each of 8th January and 15th January, he invested $n on that account. However, on 22nd January he withdrew $250 from the account due to an emergency need. If the balance on that account at the end of 31st January was $300, and the average balance for each day was also $300, then what is the approximate value of n?

A. 43
B. 55
C. 61
D. 72
E. 97

A. 43
B. 55
C. 61
D. 72
E. 97

Rs 300 deposited for 21 days (on 1st) = 300*21
Rs n deposited for 24 days (on 8th) = 24n
Rs n deposited for 17 days (on 15th)
Rs 50 deposited for 10 days (on 22nd) = 500

Average balance for the month = (300*21 + 24n + 17n + 500)/31 = 300
300*21 + 41n + 500 = 300 * 31
41n = 2500
n = 2500/41 = 61 approx

IMO C

On January 1, Ashutosh opened a current account by investing $300. On

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