[For this exercise, first write down your answer, without using R. Then, check your answer using R.]

Answers to the exercises are available here.

**Exercise 1**

Using the following variables:

x=1

i=c(1:10)

For this exercise, write a for() loop that increments x by two for each i.

**Exercise 2**

Using the following variables:

x=1

y=40

i=c(1:10)

For this exercise, write a for() loop that increments x by three and decrease y by two, for each i.

**Exercise 3**

Using the following variables:

a,b

For this exercise, write a nested for() loop (where the outer for loop increment a from 2 to 8 by 1, and the

inner for loop increment b from 1 to 6 by 1) that print “a, ‘ less than ‘,b” if a<b.

**Exercise 4**

Using the following variable:

x=c(2,4)

For this exercise, type a while () loop that adds even numbers to x, while the length of x is less than 12.

For example, in the first iteration you get `x = 2,4,6`

, and the third `x =2,4,6,8`

.

**Exercise 5**

Using the following variable:

a=15:10

b=20:15

For this exercise, type a while () loop that computes a vector` x=225 224 221 216 209 200`

,such that

x[1]=a[1]*b[6]

x[2]=a[2]*b[5]

x[3]=a[3]*b[5]

.

.

x[6]=a[6]*b[1]

```
```

**Exercise 6**

Using the following variable:

a=1:10

For this exercise, type a while () loop that computes a vector` x=1 3 6 10 15 21 28 36 45 55`

,such that

x[1]=a[1]

x[2]=a[1]+a[2]

x[3]=a[1]+a[2]+a[3]

.

.

**Exercise 7**

Using the following variable:

i=10

x=10

For this exercise, type a repeat () loop that decreasing i computes `x=x/i`

until `i=0`

.

**Exercise 8**

Using the following variable:

x=100

y=50

i=1

For this exercise, type a repeat () loop that incrementing i computes `x=x-i and y=y+i`

until `x<y`

.

**Exercise 9**

Using the following variable:

x=as.Date("10/11/2017","%d/%m/%Y")

For this exercise, type a repeat () loop that increment x until x is equal to 31/12/2017.

**Exercise 10**

Using the following variable:

x=cbind(c(1,2,3,4,9,7,4,3),c(3,1,2,5,3,6,5,3))

For this exercise, type a for() loop that calculate `y=3 8 18 44 126 140 100 84`

, such that

y[1]=x[1,1]*x[1,2]

y[2]=x[2,1]*sum(x[1:2,2])

y[3]=x[3,1]*sum(x[1:3,2])

.

.

.

y[8]=x[8,1]*sum(x[1:8,2])

**Want to practice loops a bit more? We have more exercise sets on this topic here.**

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