Step-by-step explanation:
his father's age= 4x
his mother's age= 4x- 7
his age= x
x+4x+4x-7=101
x+ 4x+ 4x= 101+ 7
9x= 108
= 
x= 12
Tesfa is 12 years old
It should be D Vietnam I believe and by the way you have this under mathematics.
Each hiker owes $41 or 4100 cents for the hiking trip.
<u><em>Explanation</em></u>
Cost of each permit is $15. So, the cost of <u>two permits</u> will be: 
Cost of each tram ticket is $19. So, the cost of <u>three tickets</u> will be:
Cost of <u>one can</u> of bear spray is $36.
So, the total cost of the hiking trip 
As the <u>three hikers</u> are dividing the total costs of the trip <u>evenly</u>, so each hiker owes
or 4100 cents.
Arc length = Ф/360 * 2πr
= 30/360 * 2*3.14*10
= 1/12 * 62.8
= 5.23
In short, Your Answer would be 5.23 cm
Hope this helps!
The greatest common factor is 2