Answer:
75years
Explanation:
Let the Father's age be represented by 2x
Let the Son's age be represented by x
Five years ago;
Man's age will be = 2x - 5
Son's age will be = x - 5
If the ratio of their ages five years ago was 9:4, then;
2x - 5/x-5 = 9/4
4(2x - 5) = 9(x - 5)
8x - 20 = 9x - 45
- Collect like terms
-20 + 45 = 9x - 8x
25 = x
Hence, the son's age = 25 years
If x = 25, the father's age (2x) will be 2 × 25 = 50years
The sum of their ages will be = 25years + 50years = 75years
 
        
             
        
        
        
Answer:
Eyelashes, wing of a fly, feather of an owl, the tip of your nose, the horn of a goat, your kidney, a maple leaf, a blade of grass, claw of a crab, and petal of a rose.
Explanation:
You have to ask yourself on each one if it is living or non-living.
 
        
             
        
        
        
Answer:
The correct answer would be the slide should be almost in focus when changing to higher magnifications.
A parfocal lens is a type of lens which stays in focus when focal length or magnification is changed.
Parfocal microscopes are those in which objectives remain in focus even when magnification is changed for example, when it is switched from 10x to 40x, the object or slide remains at the focus.