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
Remark
Make up a proportion that relates the tree and its properties to the stick and its properties.
Givens
Stick height (s_h) = 4
Stick shadow(s_s) = 2
Tree shadow = t_s = 18
Tree height = x
Formula
s_h / s_s = x / t_s
Substitute and solve.
4/2 = x / 18 Cross multiply
4*18 = 2 * x
72 = 2x Divide by 2
72/2 = x
x = 36
The height of the tree is 36 feet.
10! This is the correct answer for apex
Answer: no but some people do
Step-by-step explanation:
First row, the answer on the left , -5 3/4 - 4 2/3
