Jack is 3 times a as old as lacy. 8 years ago the sum of their ages was 25. how old are they now?

Let x = age of jack

Let y = age of Lacy

x=3y (Jack age is 3 times that of Lacy)

(x+y)-8 = 25

Substituting value of x:

(3y+y) -8 = 25

4y - 8 = 25

4y = 33

y = 33/4 = 8.25 or 8 years 3 months (age of Lacy)

x = 3(8.25) = 24.75 or 24 years 9 months (age of Jack)

Checking:

Substituting in equation ( x + y ) -8 = 25

24.75 + 8.25 - 8 = 25

25 = 25

1gm = 1000mg so 0.1gm = 1000mg

first, convert the weight to kg

160lb * 1kg/2.2lb = 72.7kg

next, the dose

72.7kg * 100mg/kg = 7270mg

answer: .64

step-by-step explanation

set up the formula for standard deviation for this set of numbers, then simplify