Grandfather

The grandfather is three years older than a grandmother. The average age of the grandmother, the grandfather, and their seven grandchildren is 28 years. The grandchildren have a total of 105 years. Calculate how old grandfather is.

Correct answer:

o =  75

Step-by-step explanation:


o = m + 3
(m+o+7•v)/(1+1+7) = 28
v = 105/7

m-o = -3
0.111111m+0.111111o+0.777778v = 28
7v = 105

m = 72
o = 75
v = 15

Our linear equations calculator calculates it.



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