2.7 Solutions

```
15 / 6 + 15 % 6
= 2 + 3
= 5
```
```
3e-1 + 2e1
= 0.3 + 20.0
= 20.3
```
```
2 / 5 * 8.0
= 0 * 8.0
= 0.0
```
```
1.6 * 20 % 8
= 32.0 % 8
= 0.0
```
```
(double)(25/4)
= (double)6
=6.0
```
```
(int)2.7 + 6.3
= 2 + 6.3
= 8.3
```

20 - 10*(15%4)
= 20 - 10 * 3
= 20 - 30
= -10

7/(-5) + 4%(-3)
= -1 + 1
= 0 Don't worry about this one we won't have to do any negative mods

```
2*3/(double)4
= 6 / 4.0
= 1.5
```
```
(int)4.8 % 1.1
= 4 % 1.1
= 0.7
```
```
6 / 4 * 2
= 1 * 2
= 2
```
```
2 * 3 / 2
= 6 / 2
= 3
```
```
(int)2.7 * 1.8
= 2 * 1.8
= 3.6
```
```
(int)2.7 * (int)1.8
= 2 * 1
= 2
```
```
(int)(2.7 * 1.8)
= (int)4.86
= 4
```

1. error, missing bracket on denominator (Actually it is correct - ironically a typo fixed the error that was supposed to be there)
2. correct
3. error, need * for multiplication
4. correct, but not as nice as (b)
5. error, numerator needs brackets
6. error, numerator and denominator both missing brackets

j = ++i * k--
j = 4 * 2       i is now 4, k is  now 1
j = 8, i = 4, k = 1

i = --j + k/2
i = 3 + 2 / 2       j is now 3
i = 3 + 1
i = 4, j = 3, k = 2

k = i-- - j++
k = 3 - 4       i is now 2, j is now 5
k = -1, i = 2, j = 5

j = (2*i++)%(++k + 1)
j = (2 * 3)%(3 + 1)       i is now 4, k is now 3
j = 6 % 4
j = 2, i = 4, k = 3

i += j -= --k
i += j = j - --k
i += j = 4 - 1       k is now 1
i += j = 3       j is now 3
i = i + j
i = 3 + 3
i = 6, j = 3, k = 1

i *= j /= k++
i *= j = j / k++
i *= j = 4 / 2       k is now 3
i *= j = 2       j is now 2
i = i * j
i = 3 * 2
i = 6, j = 2, k = 3

1. 'h' since it is 6 characters after 'b'
2. -7 since 'T' is 7 characters after 'M'

```
round(sqrt(20))
= round(4.472136)
= 4
```
```
sqrt(abs(-49))
= sqrt(49)
= 7.0
```
```
(int)random(1)
= 0
```

pow(0.5, -4)
=    1 
   0.5⁴
  
=     1  
   0.0625

= 16.0

```
sqrt(PI*abs(a*a - b*b))
```
```
pow(pow(x, 6) + pow(y, 6), 1.0/4)
```
```
(-b + sqrt(b * b - 4 * a * c)/(2 * a)
```
```
1 / (1.0 / a + 1.0 / b)
```

```
p++;
m = n * p;
n--;
```

1. They would both be equal to 4
2. ```
temp = x;
x = y;
y = temp;
```

void setup()
{
   float value1 = getFloat("Enter first number");
   float value2 = getFloat("Enter second number");
   float value3 = getFloat("Enter third value");
   float mean = (value1 + value2 + value3) / 3;
   mean = round(mean * 100) / 100.0;
   println("Rounded mean is " + mean);
}

void setup()
{
   int number = getInt("Enter a 3-digit number");
   println("The number is " + number);
   int sumDigits = number % 10;  // get last digit
   number /= 10;                 // remove last digit
   sumDigits += number % 10;     // get original middle digit
   number /= 10;                 // remove original middle digit
   sumDigits += number;          // get original first digit
   println("The digit sum is " + sumDigits);
}