Joseph is four years younger than Mary, if three times Mary’s equal four times Joseph’s age, find: a) Mary’s age b) Joseph’s age

done here

http://www.jiskha.com/display.cgi?id=1495537060

To find Mary and Joseph's ages, we can set up a system of equations based on the information given.

Let's assign variables to their ages:
Let Mary's age be M.
Let Joseph's age be J.

From the given information, we have two equations:

1) "Joseph is four years younger than Mary":
J = M - 4

2) "Three times Mary’s age equals four times Joseph’s age":
3M = 4J

a) To find Mary's age:
Substitute the value of J from equation (1) into equation (2):
3M = 4(M - 4)

Simplify and solve for M:
3M = 4M - 16
-M = -16
M = 16

So, Mary's age is 16.

b) To find Joseph's age:
Substitute the value of M from the above result into equation (1):
J = 16 - 4
J = 12

Therefore, Joseph's age is 12.

So, a) Mary's age is 16 and b) Joseph's age is 12.