forum.virtualchallengemeets.com

Hey Guys,

Gotta couple more q's. Hope you don't mind answering them...

The det ([2,3,1,4]*[4,3,1,2]) is _____________________.

Ans: 25.

The first two numbers are in the first row, and the last two numbers are in the second row, in that order.

Find k, 0<k<5, if 4k-1 = 1(mod 6).

Ans: 2.

The determinant of matrix AB is equivalent to det(A)*det(B)

Here the determinant of A=5 and the determinant of B=5, so the determinant of AB=25

Addition and subtraction are both valid(blanking on the math term) operations in modular arithmetic, you can add and subtract from both sides.

Saying that, here you have 4k=2 mod6

First see if 4k=2 has any integer solutions.

No, so now note that 8 is equivalent to 2 in mod 6, as are all other numbers in the form 2+6a.
Here we only have to check that 4k= 8 has a solution at k=2

What are the tricks for:

113 x 211?

144^2 - 89 * 233

sqrt(207936) (exact)

(67 (base 9) + 78 (base 9) ) / 8 has a remainder of ?

The largest number of regions created by 12 intersecting lines that are coplanar is ?

Thanks for the previous help. Here's another:

A golf store has white balls, yellow balls, pink balls, and orange balls. How many different packs of 3 balls can the store package?

Ans: 20.

Thanks!

I've seen problems like these:

18% of 266 and 2/3 is ?
12% of 233 and 1/3 is ?

a couple times. I there a trick, or do you just have to convert to a fraction and multiply out?

EDIT: Also, is there a trick for converting numbers like 3/14, 4/14, 5/14, etc. to percentages?

18% of 266 and 2/3 is the same thing as

18 * 2 and 2/3 which comes out as 48.

Check it on a calculator. it will be 48

same thing on 12% of 233 and 1/3

12* 2 and 1/3 = 28

Whoops!

I thought 266 and 2/3 were being multiplied should have been written as 266 2/3 instead