To replace the trees destroyed by typhoon Yolanda, the forestry department of Tagaytay has developed a ten-year plan. During the first year they will plant 100 trees. Each succeeding year, they will plant 50 more trees than they planted the year before.

a. 1,000 trees

b. 3,250 trees

Step-by-step explanation:

a. How many trees will they plant during the fifth year?

b. How many trees will they have planted by the end of the tenth year?

Using the sum of an arithmetic progression formula

Sn = n/2 {2a+(n-1)d}

Where,

Sn = Sum of an n terms

n = number of terms

a = first term

d = common difference

a.

n = 5

a = 100

d = 50

S5 = n/2 {2a+(n-1)d}

= 5/2 {2*100 + (5-1)50}

= 5/2 {200+(4)50}

= 5/2{200 + 200}

= 5/2(400)

= 2,000 / 2

= 1,000

S5 = 1,000 trees

b. Sn = n/2 {2a+(n-1)d}

n = 10

a = 100

d =50

S10 = 10/2{2*100 + (10-1)50}

= 5{200 + (9)50}

= 5{200 + 450}

= 5(650)

= 3,250

S10 = 3,250 trees

d

step-by-step explanation:

hello and welcome!

so, when we see the words "proportional" along with a table, we need to know that we're looking numbers that divide by the same thing.

looking at this table, we simply have to do a trial and error, and divide to see which numbers have the same quotient. if you look at choice a & c, they both have equal quotients for three of the numbers, with one exception, so those can't be the answer. looking at b, there is no similarity, so that can't be it. then, we see d; if you divide all the numbers in the table, you'll see that they all divide by two, which is a proportional relationship, and our answer!

also, always remember that the x will always be the number that goes into y, and somewhere behind this table, is a formula. for this specific table, the formula would be:

since our x-value is being divided by two to get the y-value. and if they were to ask for more numbers in the series, this is the formula you would use to find them.

the answer would be 150 books

step-by-step explanation:

if you divide 300 by 2 you will get 150