Step-by-step explanation: First determine whether the number increases or decreases. Since the number changes from 100 to 140 it's getting bigger, so it increases.

To find the percent increase, we use the following formula.

The amount of change is the difference between the two numbers which is 40 and we get this by subtracting 100 from 140. The original number will be the number that we started with which is 100.

140/100 simplifies to 0<em>.</em>4.

Finally, we want the percent increase so we write 0<em>.</em>4 as a percent by moving the decimal point 2 places to the right to get 40%.

Therefore, the percent increase is 40%.

6 0

2 years ago

I got this wrong on a test and I can't understand it. Can someone explain? I figured out it was compound interest, but I dont kn

Oliga [24]

A = P(1+i)ⁿ ==> compound interest where P= initial Capital, I =interest in% and n the number of years. A is the total amount collected over n years

A= 500(1.0325)¹² ==> 500(1+0.0325)¹² ==> 500(1+3.25%)¹²
The mistake is:
Either she has a yearly interest of 3.25% & she wrote 12 instead of 3 (years)
OR
She got a quarterly interest of 3.25% and in this case she should have divided 3.25& by 12 (4 quarter a year ==> 12 quarter for 3 years) by keeping as exponent the number 12 (right)

1)Now the Amount of A (as she wrote it) =500(1.0325)¹² = 734
2) If she wrote 12 instead of 3, and after correction A=500(1.0325)³ =550
3) But if she had taken the quarterly interest for a period of 3 years (12 Qrtr)
then A =500[1+(3.25%)/4]¹² = 551

3 0

3 years ago