I) What is the avg of all 3 classes? 8. IF a rectengale length and width are both doubled, by what percent is the rectangle area increase? 9. A rectangular tank by x*y*z is filled with water.if all the water is transferred to cube shape tanks,each one is p inches on a side.how many small tanks require?(x,y,z,p are variables) 10..A father is three times as old as his son.After 15 years the father will be twice as old as his sons age at that time.Hence the father's present age is? (The data are not same with the question set but the pattern was same.)