1) in first place , calculate the rate with the values given
r= 120-4/60-2 = 2, , now you need to Know which is the number of weeks contained in 70 days, ok, 1 week____ 7 days
x------------70 days , resolving it x = 10 weeks
2) Now as you Know the numbers of week and is 10 , you must establish a relation of proportion
$120/________4 weeks
$ X ___________ 10 weeks
X = $120*10 WEEKS / 4 WEEKS, X = $ 300, the quantity that a person can save to the end of tens weeks
