Answer:
1. Steve's age is 18 and Anne's age is 8.
2. Max's age is 17 and Bert's age is 11.
3. Sury's age is 19 and Billy's age is 9.
4. The man's age is 30 and his son's age is 10.
Explanation:
1. Let us assume that:
S = Steve's age now
A = Anne's age now
Therefore, in four years, we have:
S + 4 = (A + 4)2 - 2
S + 4 = 2A + 8 - 2
S + 4 = 2A + 6 .................. (1)
Three years ago, we have:
S - 3 = (A - 3)3
S - 3 = 3A - 9 ................................ (2)
From equation (2), we have:
S = 3A - 9 + 3
S = 3A – 6 …………. (3)
Substitute S from equation (3) into equation (1) and solve for A, we have:
3A – 6 + 4 = 2A + 6
3A – 2A = 6 + 6 – 4
A = 8
Substitute A = 8 into equation (3), we have:
S = (3 * 8) – 6
S = 24 – 6
S = 18
Therefore, Steve's age is 18 while Anne's age is 8.
2. Let us assume that:
M = Max's age now
B = Bert's age now
Therefore, five years ago, we have:
M - 5 = (B - 5)2
M - 5 = 2B - 10 .......................... (4)
A year from now, we have:
(M + 1) + (B + 1) = 30
M + 1 + B + 1 = 30
M + B + 2 = 30 .......................... (5)
From equation (5), we have:
M = 30 – 2 – B
M = 28 – B …………………… (6)
Substitute M from equation (6) into equation (4) and solve for B, we have:
28 – B – 5 = 2B – 10
28 – 5 + 10 = 2B + B
33 = 3B
B = 33 / 3
B = 11
Substituting B = 11 into equation (6), we have:
M = 28 – 11
M = 17
Therefore, Max's age is 17 while Bert's age is 11.
3. Let us assume that:
S = Sury's age now
B = Billy's age now
Therefore, now, we have:
S = B + 10 ................................ (7)
Next year, we have:
S + 1 = (B + 1)2
S + 1 = 2B + 2 .......................... (8)
Substituting S from equation (7) into equation (8) and solve for B, we have:
B + 10 + 1 = 2B + 2
10 + 1 – 2 = 2B – B
B = 9
Substituting B = 9 into equation (7), we have:
S = 9 + 10
S = 19
Therefore, Sury's age is 19 while Billy's age is 9.
4. Let us assume that:
M = The man's age now
S = His son's age now
Therefore, now, we have:
M = 3S ................................... (9)
Five years ago, we have:
M - 5 = (S - 5)5
M - 5 = 5S - 25 ................ (10)
Substituting M from equation (9) into equation (10) and solve for S, we have:
3S - 5 = 5S – 25
3S – 5S = - 25 + 5
-2S = - 20
S = -20 / -2
S = 10
Substituting S = 10 into equation (9), we have:
M = 3 * 10
M = 30
Therefore, the man's age is 30 and his son's age is 10.