1) In 3 yrs., Alex will be 3 times as old as his sister Precy. A year ago, Alex was 7 times as old as Precy. How old are they now?
2) Riza was 25 when her first born son was born. Today the sum of their ages is 105. How old is Riza and her son now?
2007-07-20 01:24:14 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
a, p are the ages now.
a+ 3 = 3(p + 3)
a - 1 = 7(p - 1)
solve for a in the first: a = 3p + 6, and use this in the second which will then be in p only.
r is Riza's age, s the son's.
r = 25 + s
r + s = 105, so r = 105 - s. Use this in the first which will be in s only.
2007-07-20 01:31:32 · answer #1 · answered by John V 6 · 0⤊ 0⤋
Q2) Riza=x old
Son=x old...
105-25= 80....
80 divided by 2=40....
Son=40...
then...
40+25=65
Riza=65...
65+40=105
2007-07-20 08:32:04 · answer #2 · answered by onewayorother 2 · 0⤊ 0⤋
a+3=3(p+3)
a-1=7(p-1)
p=3
a=15
2)
25+x+0+x=105
x=40
r=25+40=65
son=40
2007-07-20 08:29:48 · answer #3 · answered by iyiogrenci 6 · 0⤊ 0⤋
do it yourself!
2007-07-20 08:25:44 · answer #4 · answered by Posiedon 3 · 0⤊ 1⤋