Question

The senior class spent 20% of its budget on a box of tomatoes. It then spent one - fourth of the remaining funds on a helium blimp. Finally, it spent $\dfrac{1}{3}$ of the remaining funds on an extra-large helicopter for the prom. Calculate the percentage of the original funds not spent.
A) 20%
B) 25%
C) 40%
D) 50%
E) 60%

Answer 1

Hint: In the above question we have to find the remaining percentage of the given expenditure. So here we will assume the total funds $100\%$ to calculate the overall funds which are not spent.

Complete step by step answer:
Let the original funds be $100\%$.
So, it is given that $20\%$ of the funds are spent on tomatoes.
Therefore, we should subtract the percentage of funds spent on tomatoes from the original funds. We get,
$\Rightarrow 100 - \dfrac{{20}}{{100}} \times 100 = 80\% $
Thus, the remaining fund is $80\%$.
Also, it is given in the question that after spending on tomatoes one – fourth of the remaining funds are spent on helium blimp:
We get,
$\Rightarrow \dfrac{1}{4} \times 80\% = 20\% $
Now, our remaining funds is $80\% – 20\% = 60\%$
Again, it is given in the question that from the remaining funds that are $60\%$ he spent one – third on the extra-large helicopter so, the percentage spent is:
$\Rightarrow \dfrac{1}{3} \times 60\% = 20\% $
So, original funds not spent is ($60\% – 20\% = 40\%$)

$\therefore $ The percentage of the original funds not spent is $40\%$. The correct option is option (A).

Note:
Students should keep in mind that they should assume the original fund to be 100. This will help them in calculating all the expenses easily. You should also consider one thing before solving this question that if it is given that the senior class spent one – fourth of the “remaining funds” on a helium blimp. Then we will do our calculation on the remaining funds not on the original fund.