In 1950, Richard was 4 times as old as Robert. In 1955, Richard was 3 times as old as Robert. In which year was Richard 1.75 times as old as Robert?	Choose the correct answer:
A) 1960
B) 1965
C) 1970
D) 1975
E) 1980
In 1950: Ri = 4 Ro -------------- eq1   In 1955: Ri +5 = 3(Ro+5)---------eq2   Thus in 1950, solving eq1 and eq2   Ro= 10 , Ri =40   Now for each year we can calculate:   1960: Ri = 50 , Ro =20   1965: Ri= 55, Ro=25   1980: Ri= 40, Ro = 70   Thus8Ans:1980
<result>E</result>
In 1950, Richard was 4 times as old as Robert. In 1955, Richard was 3 times as old as Robert. In which year was Richard 1.75 times as old as Robert?