A teacher working's day is 7 1/2 hours long. one certain day, he spent 3 1/2 hours teaching and 2 1/2 hours marking student assignment. What fraction did he spend (a) Teaching (b) Marking.​

(a) 7/15

(b) 1/3

Step-by-step explanation:

(a) teaching:

(3 1/2) / (7 1/2) = (7/2) / (15/2) = 7/2 * 2/15 = 7/15

(b) marking:

(2 1/2) / (7 1/2) = (5/2) / (15/2) = 5/2 * 2/15 = 5/15 = 1/3

solution:

the given function is ,

      =

the three roots of this quadratic function is , 0 ,8 and 10.all the roots are real and rational.

if a quadratic equation is of the form ,

sum of the roots = a + b +c= 0+8+10=18=  

product of roots taken two at a time = a b + b c+ c a = 0+80+0=80 =  

product of roots = a b c = 0=  

there are 11 doors in a hall starting from 0 to 11.the entry in the hall is permitted through gate number 0 and exit is allowed through only gate number 8 and 10.so, three roots(0,8,10) of quadratic function is given by entry and exit route of this hall.

a

step-by-step explanation: