

1 
Word Problems. MultiChoice Practice. (10 possible
points).

Bill
rode his skateboard (with a helmet) 25 miles in 80 minutes. How
many miles can he ride his skateboard in 60 minutes (at the same pace)? 

Aurora HC212
8 digit, Solar / Battery power calculator 
Formula: 25 _{=} x
80 60
25 * 60 = 80x cross multiply
25 * 60 ÷ 80 = x isolate for x
x = 25*60÷80
Calculator: 25x60÷80=
Start off by setting it up mathematically.
Setup: 25 mi _{ =} x mi
80 min 60 min
25 miles in 80 minutes is expressed as 25 mi 80 min
How many miles in 60 minutes is expressed as x mi 60 min
First step: Cross multiply: 60*25 = 1500 (60 times 25. done below)
so 1500 = 80x
1500 equals 80x (80 * x)
2nd step: Isolate x by dividing each side by 80.
1500 _{= }80x _{ }80x 80 80 80 cancels to x
_{Third step: Rewrite as} _{x}_{ = 1500 } ^{ 80}
4th step: Divide 1500 by 80, equals 18.75.
^{ T}^{he answer is 18.75 miles in 60 mins}^{ (mph) }^{. }
1 

1. cross multiply: 60x25 = 1500
so 1500 = 80x
1500 equals 80x
Calculator: press 60X25= (60x25 =
1500)
(= sign gives result)
Note the ÷,x,,= signs. 

2 

divide 1500 by 80 by pressing
÷80=
(divide sign, 80, equal sign)
result is 18.75 miles in 60
mins.
(fast for a skateboard) 

Choose the letter of the correct
answer:
A. 17 B. 18
C. 18.75 D. 20 and enter it in the answer box below:



Answer Box.
Check it with the Test Button.


4 


Given
what
does x^{2 }equal when x = 2?
Ans. 2^2 = 4 (Rule 1)
x ^{2
}
equal
when x = 1? ..... 1^2 = 1
(Rule 1)
x^{2 }equal when x = 0?"
..... 0^2 = 0 (0*0)
x^{2
}
equal
when x = 1? ..... 1^2 =
1 (1*1)
x^{2 }equal when x = 2? .....
2^2 =
4 (2*2)
x ^{1
}
equal when x = 2? .....
2^1 = 2 (Rule 2)
x^{0}
equal when x =
2? ..... 2^0 = 1 (Rule 3) 2^{1/2} =
2^2
=
(½ * ½ = ¼) = 0.5 * 0.5 = 0.25
(Rule 4)
Rule
1: A negative number raised to any power stays negative.
2: Any number raised to the 0 power is
1.
3a: A positive number raised to the 1 power is
itself.
3b: A negative number raised to the 1 power is
itself.
4. A negative power becomes its positive reciprocal.
Raising Negative Numbers:
Example: Raise 2 to the 5th power. (Apply Rule 1: A negative
number raised to any power stays negative.) So 2^{5}
equals 32.
On my calculator, I typed 2^5= and got 32. By penandpaper, I
did 2*2*2*2*2 = 32 then prefixed it with a minus () sign. (unary
operations performed last.)
                
Raising a Number to 0 power:
Raise 2 to the 0 power. (Apply Rule 2: Any number to
the 0 power is 1.)
So 2^{0}
equals 1.
         
      
Raising a Number to 1 power:
Raise 2 to the 1 power. (Apply Rule 3: Any number to
the 0 power is 1.)    