Geometric sequences

2010004903

Level: 
A
The seventh term of a geometric sequence is \( 32 \) and the tenth term is \( 4 \). Choose the correct formula to find the eighth term of this sequence.
\( a_8=32\cdot\sqrt[3]{\frac4{32}} \)
\( a_8=32\cdot\sqrt[3]{\frac{32}4} \)
\( a_8=4\cdot\sqrt[3]{\frac4{32}} \)
\( a_8=4\cdot\sqrt[3]{\frac{32}4} \)
\( a_8=8\cdot\sqrt[3]{\frac3{24}} \)

1003134603

Level: 
B
The sum of the first five terms of a geometric sequence is less than $1$ and the common ratio is $10$. Determine all possible values of the first term.
$ a_1 < \frac1{11111}$, $a_1\in\mathbb{R}$
$ -\frac1{10^5} < a_1 < \frac1{10^5}$, $a_1\in\mathbb{R}$
$a_1 < \frac1{99999}$, $a_1\in\mathbb{R}$
$a_1 < 10^{-4}$, $a_1\in\mathbb{R}$
$a_1 < 10^{-5}$, $a_1\in\mathbb{R}$

1003158507

Level: 
C
Let there be a row of five yellow cubes lying side by side. The first cube has an edge length of \( 100\,\mathrm{cm} \) and each next cube has an edge length by \( 10\,\mathrm{cm} \) shorter than the previous one. Let there be a second row of five blue cubes lying side by side. The first blue cube has an edge length of \( 100\,\mathrm{cm} \) and each next cube has an edge length by \( 10\% \) smaller than the previous one. What is the difference between the length of these two rows?
\( 9.51\,\mathrm{cm} \)
\( 34.51\,\mathrm{cm} \)
\( 0\,\mathrm{cm} \)
\( 20\,\mathrm{cm} \)
\( 20.51\,\mathrm{cm} \)