The initial amount of the money is £11,000 and the interest is 3.9% per year for first 3 years and then 4.5% after that. If Dan invests it for 7 years, that means the interest would be 3 years of 3.9% and 4 years of 4.5%.
The calculation would be:
total money= initial amount * interestrate1 * interest 2
total money= £11000 *(100%+3.9%)^3<span>*(100%+4.5%)^4
</span>total money= £11000 *(103.9%)^3 * (104.5%)^4
total money= £11000 * <span>1.121622319 </span>* 1.1925186
total money= £14,713.11
<span>The lowest common denominator of 5/42 and 7/30 is 210.</span>
We can create equations to solve this.
2.50p + 1.50m = 29.50
p + m = 15
Solve for a variable in the 2nd equation and use the substitution method to solve.
p + m = 15
Subtract p to both sides:
m = -p + 15
Plug in -p + 15 for m in the first equation.
2.50p + 1.50(-p + 15) = 29.50
Distribute:
2.50p - 1.50p + 22.50 = 29.50
Combine like terms:
p + 22.50 = 29.50
Subtract 22.50 to both sides:
p = 7
Now plug this into any of the two equations and solve for the other variable.
p + m = 15
7 + m = 15
Subtract 7 to both sides:
m = 8
So he purchased 7 pineapples and 8 mangos.
