Question

Вкладчик снял со своего счнта в сбербанке сначала 1/4 вклада, затем 4/9 оставшихся денег и ещё 640 руб. После этого у него осталось на счету 3/20 всех его денег. Как велик был вклад?

Answer 1

Х руб. было на вкладе
снял 1/4х, осталось 3/4х
затем снял 3/4х*4/9=1/3х
х-1/4х-1/3х-640=3/20х
45х-20х-9х=38400
16х=38400
х=2400 руб. составлял вклад

Answer 2

Calculating the Size of the Deposit

To calculate the size of the deposit, we can use the information provided in the question and solve for the original amount of money deposited.

Let's denote the original deposit amount as D.

1. The depositor first withdraws 1/4 of the deposit. 2. Then, 4/9 of the remaining money is withdrawn, along with an additional 640 rubles. 3. After these withdrawals, 3/20 of the total money remains in the account.

We can set up the following equation to represent the given information:

D - 1/4D - 4/9(D - 1/4D) - 640 = 3/20D

Now, let's solve for D using this equation.

Solving for the Deposit Amount

First, let's simplify the equation step by step.

1. D - 1/4D represents the amount remaining after the first withdrawal. 2. D - 1/4D - 4/9(D - 1/4D) represents the amount remaining after the second withdrawal. 3. Adding the additional 640 rubles to the second withdrawal amount.

Now, we can solve for D using the given equation.

Calculation

D - 1/4D - 4/9(D - 1/4D) - 640 = 3/20D

Simplify the equation: D - 1/4D - 4/9D + 1/9D - 640 = 3/20D

Combine like terms: D - 4/9D + 1/9D - 3/20D - 640 = 0

Find a common denominator: 180D - 80D + 20D - 27D - 5760 = 0

Combine like terms: 93D - 5760 = 0

Add 5760 to both sides: 93D = 5760

Divide by 93: D = 5760 / 93

Result

D = 60

So, the original deposit amount was 60 rubles.