Okay, so the rate is 1 job / hours, so:
1/3 + 1/7 (This covers both their work rates) = 1/n (n represents the time it take for them to work together)
Get the LCD:
7/21+ 3/21 = 1/n
10/21 = 1/n
Cross multiply:
10n = 21
n = 2.1
It will take them 2.1 hours, or 2 hours and 6 minutes
Answer:
Answer
see explanation
Step-by-step explanation:
Using the rule of exponents
= , then
=
His mistake was in subtracting 3 rather than - 3
she drove 40 mph & 60 mph
60 +40 = 100
100/2 = 50
so she drove an average of 50 mph
Answer:
4/5
Step-by-step explanation:
Sin = Opposite / Hypotenuse
Note that hypotenuse = longest side
We want to find sinФ
The opposite side length of angle "Ф" has a length of 8 and the longest side or hypotenuse has a length of 10
So sinФ would equal 8/10 which can be simplified to 4/5
