Let your grandfather's age be x, then
for some integers: p, q and r.
Solving for x in the 3 equations we have:
From eqtn (4), possible values of x: 9, 16, 23, 30, 37, 44, 51, 58, 65, 72, 79, 86, 93, 100
From eqtn (5), possible values of x: 8, 13, 18, 23, 28, 33, 38, 43, 48, 53, 58, 63, 68, 73, 78, 83, 88, 93, 98
From eqtn (6), possible values of x: 16, 27, 38, 49, 60, 71, 82, 93, 104
Notice that the only number that appeared in all three is 93.
Therefore, your grandfather's age is 93 years old.
for some integers: p, q and r.
Solving for x in the 3 equations we have:
From eqtn (4), possible values of x: 9, 16, 23, 30, 37, 44, 51, 58, 65, 72, 79, 86, 93, 100
From eqtn (5), possible values of x: 8, 13, 18, 23, 28, 33, 38, 43, 48, 53, 58, 63, 68, 73, 78, 83, 88, 93, 98
From eqtn (6), possible values of x: 16, 27, 38, 49, 60, 71, 82, 93, 104
Notice that the only number that appeared in all three is 93.
Therefore, your grandfather's age is 93 years old.