So 2 miles per 1/2 hour
therfor 1 mile in 1/4 hour since 1/4 is 1//2 of 1/2
so
1 mile per 1/4 hour
2 mile per 2/4 hour
3 mile per 3/4 hour
basically 2 times 3/2=3 so
1/2 times 3/2=3/4=answer
171 dollar because 1170 divde by 19.5 is 60 times 2.85 is 171
<span>let x = the original no. of students
then
(x+10) = the actual no. that went on the trip
:
= the original cost per student
and
= the actual cost
:
Original cost - actual cost = $12.50
- = 12.50
multiply equation by x(x+10)
x(x+10)* - x(x+10)* = 12.50x(x+10)
Cancel the denominators
1500(x+10) - 1500x = 12.5x(x+10)
1500x + 15000 - 1500x = 12.5x^2 + 125x
Combine on the right to form a quadratic equation
0 = 12.5x^2 + 125x - 15000
Simplify, divide equation by 12.5
x^2 + 10x - 1200 = 0
You can use the quadratic formula; a=1; b=10; c=-1200, but this will factor to
(x + 40(x - 30) = 0
The positive solution is what we want here
x = 30 students in the original group
Check this by finding the cost per student for each scenario
1500/30 = $50.00; original cost
1500/40 = $37.50; actual cost
---------------------
saving: $12.50</span>
When you are told to estimate, you should be able to do the problem in your head.
8 7/12 is close to 8 1/2
4 7/8 is very nearly 5
4/10 is very nearly 1/2
8 1/2 - 5 - 1/2 First of all you can take the 1/2 away from 8 1/2
8 1/2 - 1/2 = 8
Now take away the 5
8 - 5 = 3
So the answer is very nearly
3 <<<<< answer.
Just for fun, I'll get the exact answer. Don't hand this one in. It is 3 37/120
You learn to estimate because you are trying to guess whether or not you've entered everything correctly into your calculator. When writing a test, this is a very handy skill to have developed.
<span>The power of a number says how many times to use the number in a multiplication. It is written as a small number to the right and above the base number.</span>
