1. Is 8 seconds
2. I think is 15 quartz sorry if I’m wrong
A²=25 then a = + 5 & a =-5, so this ellipse intercepts the x axis at the points +5 & -5
If 8 is the first term, there are 17 terms left to reach the 18th term. So you do -2 x 17 = -34 then do 8 - 34 = -26
Given:
Dimensions of a block are
.
To find:
The number of block that can be fit in a unit cube.
Solution:
Volume of a cuboid is:

Where, l is length, b is breadth or width and h is the height of the cuboid.
So, the volume of the given block is:


Dimensions of a unit cube are
. So, the volume of the unit cube is:


We need to divide the volume of unit cube by the volume of a block to find the number of block that can be fit in a unit cube.
So, the number of blocks that fit in a unit cube is:



Therefore, the correct option is B.