Question

Jason started with d dollars in his piggy bank. One week late, Jason doubled the amount in his piggy bank. Another week later, jason was able to add $20 to his piggy bank. At this point, the piggy bank had $50 in it. What is d?

Answer 1

Given, Jason had an amount of $d in the piggy bank.

After one week, Jason doubled the amount in the piggy bank.

So, after one week the amount in the piggy bank = $$(2)(d)$ = $(2d)

Another week later, Jason added $20 in the piggy bank.

So after another week, the total amount in the piggy bank = $$(2d+20)$

Given, that time the piggy bank had $50 in it.

So we can write the equation as,

$2d+20 = 50$

To find the value of d, we will move 20 to the right side by subtracting it from both sides. We will get,

$2d+20-20 = 50 - 20$

$2d = 50 -20$

$2d = 30$

Now to find d, we will move 2 to the right side by dividing it to both sides. We  will get,

$\frac{2d}{2}=\frac{30}{2}$

$d = 15$

We have got the required answer.

The value of d = $15.