What is the sum of all the even numbers from 20 to 70

the even numbers starting from 20 to 70 when being add form an A.P

the first term being 20 the last term 70 and common difference = 2

Let us first find the number of terms in it

suppose 70 is the nth term .

nth term of A.P= a+ ( n-1) d here a= 20 and d = 2

70 = 20 +( n-1) * 2

70-20 = (n-1)*2

50= (n-1)*2

50/2 = n-1

25 = n-1

25 +1 = n

26 = n

let us now find sum of these 26 terms

sum formula for n terms = n ( 2a+ ( n-1) d)

2

26 ( 2* 20 + ( 26-1)* 2)

2

13 ( 40 + 25 * 2)

13 ( 40 +50 )

13 ( 90 )

1170 Answer.

22,24,26,28,32,34,36,38,40,42,44,46,48,52,54,56,58,60,62,64,66,68

f(h) = 0.004s + 37

Step-by-step explanation:

The correct representation of the height of the plant is;

          f(h) = 0.004s + 37

Given parameters;

  Height of plant  = 37cm

  Rate of growth  = 0.004cm/hr

  Number of hours of sunlight  = s

To solve this problem, the height of the plant is directly dependent on the amount of sunlight;

     f(h) signifies that height is a function

The height of the plant is 37cm;

         f(h) = 37

The plant grows at a rate of 0.004cm/hr;  number of hours of sunlight is s;

       0.004s

Therefore;

  f(h) = 37 + 0.004s