M=3S
M+10+S+10=76
3S+10+S+10=76
4S=56
S=14
M=3*14
A MAN is now 3 times as old as his son. In 10 years time, the sum of their ages will be 76. How old the son.
3 answers
(x+10) + (3x+10) = 76
M = 3S
(M+10) + (S+10) = 76
Substitute 3S for M in the second equation and solve for S. Insert that value into the first equation to solve for M. Check by putting both values into the second equation.
(M+10) + (S+10) = 76
Substitute 3S for M in the second equation and solve for S. Insert that value into the first equation to solve for M. Check by putting both values into the second equation.