Find the sum of the first 20 terms of an arithmetic series if the first term is 10 and the twentieth term is 38.

[arithmetic sequences]

if correct

480

Step-by-step explanation:

To find the sum of the first n terms of an arithmetic series use the formula, n terms of an arithmetic sequence use the formula,

Sn=n(a1 + an)2

n=20

a1= 10

a20=38

20(10+38)/2

20(48)/2

960/2

480

So the ans is 480

for a it would be 24 children.

for b i don't understand the question. is it saying for each individual person they pick 5 reds to 7 greens or is it the whole group. clarify and i hope this can you.

step-by-step explanation:

b) k’(6, 4); l’(3, 3)

step-by-step explanation:

a 270° clockwise rotation maps every point (x, y) to (y, -x). (it negates the x-coordinate and then switches it and the y-coordinate.)

this means the endpoints of the side congruent to kl, k' and l', would be mapped as:

k'(-4, 6)→(6, 4)

l'(-3, 3)→(3, 3)