Answer:
13/35
Step-by-step explanation:
13 students choose football.
31 students choose tennis.
this leaves 26 students that chose running.
probability of choosing running is 26/70 = 13/35
Hi there
The rule of 72 is
72/rate=time
72÷3=24 years
Hope it helps
Answer:
Cost price = 200
Profit = 230-200 = 30
Step-by-step explanation:
x + 15/100x = 230
x + 3/20x = 230
20x + 3x = 4600
23x = 4600
x = 200
Answer:
<u>135.73 ounces</u> of a silver alloy that costs $5.50 per ounce should be mixed.
Step-by-step explanation:
Given:
A silver alloy that costs $5.50 per ounce should be mixed with one that costs $7.00 per ounce to make a new 30 ounce alloy that costs $6.40 per ounce.
Now, to find the ounces of silver alloy.
Let the silver costs $5.50 per ounce be 
And the silver costs $7.00 per ounce be 
So, the total ounce make a new alloy:
....(1)
Now, the total costs of silver alloy:

Putting the value of
from equation (1) in the place of
:



<em>Subtracting both sides by 210 we get:</em>

<em>Dividing both sides by -1.5 we get:</em>

Therefore, 135.73 ounces of a silver alloy that costs $5.50 per ounce should be mixed.