The fortieth odd number is
81
39
79
41
and the sum of the first forty odd numbers is
80
1600
158
6241

1) Third Option is correct.

2)  Second Option is correct.

Step-by-step explanation:

Since we have given that

odd numbers are as follows:

1, 3, 5, .........................

so, first term = a = 1

d = common difference = 3-1=2

n =  number of terms = 40

As we know that it forms an "Arithmetic Progression ":

so, the fortieth odd number is 79.

Hence, Third Option is correct.

Now, we need to find the first forty odd numbers :

As we know the formula :

Hence, Second Option is correct.  

proportions are fractions that equal to each other. so if two fractions are the same, they are proportional.

let's check the answers to see if they are proportional.

question a is not proportional because you can't turn 1.5/3 to 3/9. if you try to multiply 1.5/3 by 2 or 3, you wont get 3/9. it's impossible to make the fractions the same.

question b is not proportional because you can't turn 22/33 to 4/6. 33 can't go into 6.

question c is proportional because when you multiply 2 and 3 by 71, you would get 142/213, and those fractions equal to each other

question d is proportional because when you divide 14 and 7 by 2, you would end up with 7/3.5, and those fractions equal to each other.

step-by-step explanation:

need