Answers:
- <u>24000 dollars</u> invested at 4%
- <u>18000 dollars</u> was invested at 7%
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Work Shown:
x = amount invested at 4%
If she invests x dollars at 4%, then the rest (42000-x) must be invested at the other rate of 7%
She earns 0.04x dollars from that first account and 0.07(42000-x) dollars from the second account
This means we have
0.04x+0.07(42000-x)
0.04x+0.07*42000-0.07x
0.04x+2940-0.07x
-0.03x+2940
This represents the total amount of money earned after 1 year.
We're told the amount earned in interest is $2220, so we can say,
-0.03x+2940 = 2220
-0.03x = 2220-2940
-0.03x = -720
x = -720/(-0.03)
x = 24000 dollars is the amount invested at 4%
42000-x = 42000-24000 = 18000 dollars was invested at 7%
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As a check, we can see that
18000+24000 = 42000
and also
0.04x = 0.04*24000 = 960 earned from the first account
0.07*18000 = 1260 earned from the second account
1260+960 = 2220 is the total interest earned from both accounts combined
This confirms our answers.
Answer:
2744 pennies.
Step-by-step explanation:
Let x represent the number of pennies Al have initially.
We have been given that Al agreed to give 3/7 of his pennies to Bev, so number of pennies Bev will get would be 
.
We are also told that Bev gave 3/7 of what she got from Al to Carl, so number of pennies that Carl will get would be 
.
Further, Carl gave 3/7 of what he got from Bev to Dani, so number of pennies that Dani will get would be 
.
We are also told that Dani received 216 pennies. Now, we will equate 216 to 
and solve for x as shown below:
Therefore, Al have 2744 pennies initially.
Answer:
<h2>
46</h2>
Step-by-step explanation:
x - age of a son three years ago
3x - age of a father three years ago
x + 3 - age of the son now
3x + 3 - age of the father now
x + 3 + 5 - age of the son in five years time
3x + 3 + 5 - age of the father in five years time
in five years time, the father will be twice as old as his son, so:
3x + 3 + 5 = 2(x + 3 + 5)
3x + 8 = 2x + 16
3x - 2x = 16 - 8
x = 8
x + 3 + 4 - age of the son in four years time
8 + 3 + 4 = 15
3x + 3 + 4 - age of the father in four years time
3×8 + 3 + 4 = 31
the sum of their ages in four years time:
15 + 31 = 46
