Whenever you see the word "per" you can ALWAYS substitue in the word "divide". When you see "miles per gallon", change "per" into "divided by" to get miles divided by gallons. That is how you will solve the problem.
SO.....
300 miles ÷ 10 gallons = 30 miles per gallon
<u>The present age of the man is 36 years and his son is 11 years.</u>
Answer:
Solution given:
let the age of man be x.
and his son be y.
By question
x-6=6(y-6)
x=6y-36+6
x=6y-30. ......(1)
and
3(x+4)=8(y+4)
3x+12=8y+32
3x=8y+32-12
3x=8y+20. ...(2)
substituting value of x in equation 2 ,we get
3(6y-30)=8y+20
18y-90=8y+20
18y-8y=90+20
10y=110
y=110/10
y=11 years
again substituting value of y in equation 1 we get
x=6*11-30
x=66-30
x=36 years
There is a lot of numbers
7(5)-12(5)-5=-45+15
-30 = -30
answer= B. x=5
C the bank will exchange his new car for a old one