More Questions

[thatoneguy]

(321 base8)(456 base 8) / 7 has a remainder of?

If 9^(x-1) = 27^(x+2) then x=?

15*(16/17)

90+60+40+26.666+...=?

The reciprocal of 3+4i is a+bi. Find b

1+3+8+21+...+144=?

1^2+2^2+3^2...+11^2+12^2=?

Find k, so that 917k55 is the smallest 6 digit number divisible by 11

If A is 24% more than B and B is 25% more than C, then A is____% more than C

48^2 + 76^2

If 77^2 + k^2 = 9898 then k=?

144^2 - (89)(233)
89^2 - (144)x= 1 Find x

How many ways can Donald and his 3 nephews sit in a row of 5 chairs?

[nsguy1350]

When the divisor is one less than the base of the dividend, just add the digits of each number and perform the necessary operation. This is equivalent to base 10 divided by base 9 - add up add of the digits then perform the operation.
You get (6)(15) divided by 7 = 6. The 6 and 15 are independent of base 7 and 8, multiplying gives 90 base 10, resulting in 6. I'm not 100% sure on this trick but I think this works.

[unparseable or potentially dangerous latex formula]

15 x 16/17 = 16 x 16/17 - 16/17 = 15 1/17 - 16/17 = 14 2/17. This is the trick a x a/b , but you have to subtract a/b at the end because it's (a-1) x a/b.

Sum of infinite geometric series is [unparseable or potentially dangerous latex formula] a is your first term, r is your common ratio between terms. You can see that 90 x 2/3 = 60, 60 x 2/3 = 40, etc.

The reciprocal is in the form [unparseable or potentially dangerous latex formula]. divide (-b) by the denominator to get 4. This is -4/25.

This is the sum of even indexed Fibonnacis, which is the next odd Fibonnaci minus 1, or 233 - 1 = 232.

Sum of first n cubes = nth triangular number squared. [unparseable or potentially dangerous latex formula].

The remainder when dividing by 11 is the even indexed numbers minus the odd indexed numbers, mod 11, or the smallest positive remainder when the above result is divided by 11.
You get (1+k+5)-(9+7+5) = k-15 which has to be divisible by 11. This means k = 4.

A = 124/100 B = 31/25 B. B = 125/100 C = 5/4 C.
A = 31/25 x 5/4 C = 155/100 = 55% more.

The outside numbers, 4 and 6, add to 10, while the second number is one more than the first. This means square the digits of the left number, add the squares, then multiply by 101. You get 4^2 + 8^2 = 80, 80x101 = 8080.

Same thing, you see the 9898 = 98x101, and 7^2 + 7^2 = 98. This means that the first number of the new number is 6 (one less than 7), and the last number of the new number is 3. Answer shuld be 63.

[unparseable or potentially dangerous latex formula]. The Fibonnaci after 89 is 144, so you need the one before 89, which is 55. As you can see, this equals 1. You can see if it's positive or negative one by squaring the first ones digit and multiplying the ones digits of the others; 89^2 ends in 1, while 144 x 55 ends in 0, resulting in positive 1.

5P4 = 120.

Hopefulle everything above is correct, sorry if I made a dumb mistake or bad typo.