Answer:
$68.99
Step-by-step explanation:
This is called percentage decrease:
(100 - 72)% = 28%
246.40 × 28/100
= $68.99
Let's have a variable for each rate
x = account 1 (2.5% rate of interest)
y = account 2 (8% rate of interest)
The formulas we need are:
0.025x + 0.08y = 830 (amount of interest paid)
x + y = 20 000 (combined amount invested)
To solve we will use substitution (isolate for one variable and plugging into the other formula):
x + y = 20 000
x = 20 000-y
0.025x + 0.08y = 830
0.025(20 000-y) + 0.08y = 830
500-0.025y+0.08y=830
500+0.055y=830
0.055y=330
y=6000
Now that we know y (the 2nd account) = $6000 we need to find x. We do this by using the previous formula.
x = 20 000-y
x=20 000 - 6000
x=14000
She invested $14 000 at a 2.5% interest rate and $6 000 at a 8% interest rate.
*Notes:
the percentages were converted into decimal form
you check your answer by plugging the numbers back into the 2 formulas we made
£15
If you add the two ratios together you get 10. Which means that the £50 is made up of 10 pieces. To get Doras amount you have to divide 50 by 10 which is five, and then times the number by how many pieces Dora has, which would be 5x3=15
