some math problems?

Question

1. 10 is what percent of A?
a.) 10A%.
b.) 1/10A%
c.) 10/A%
d.) 100/A%
e)1000/A%.

2. A rectangle has a perimeter equal to the circumference of a circle of radius 3. If the width of the rectangle is 3, what is its length?

3. What is the remainder when 5^20 is divided by 100??

Answer 1

Hi Nicole,

(1) The correct answer is "e": 10 / A x 100 % = 1000/A %

(2) The perimeter is 2xLength + 2xWidth = 2*Pi*3, right? From this, Length = 1/2 x ( 6Pi - 2x3), or Length=3*Pi-3

(3) Any two numbers ending by 5 multiplied give you "25" in the end. Hence, the remainder is 25.

Answer 2

1. 10/A x 100% = 1000/A%
2. the formula for perimeter of rectangle is 2l+2w
the formula for the circumference is 2piR

so we have

2l+2w=2piR
by substitution
2l+2(3)=2pi(3)
2l+6=6pi
2l=6pi-6
l=6(pi-1)/2
l=3(pi-1)
l=6.4247779607693797153879301498385

the length is approximately 6.42 of whatever unit

3. any 2 numbers ending in 5 when multiplied yields a n umber ending in 25
and any number divided by one hundred yields a number which the last two numbers are seperated by a decimal point.

example:
5x5=25
25x25=625
625x5=3125

3125/100=31.25

therefore
5^19x5=n25

therefore
n25/100=n.25

so the remainder is 25

Answer 3

1. e)1000/A%.
2.
P = 6π = 2(L + 3)
L + 3 = 3π
L = 3(π - 1) ≈ 6.424778
3.
(5^20)mod100 = 25
(5^n)mod100 = 25, n >1

Answer 4

1.I think it is c

2. I cannot understand the ansewr I don't know english definitions.

3.95367431640625/100=953674316406.25