P&H 4.1

0000 0000 0000 0000 0000 0010 0000 0000

P&H 4.2

1111 1111 1111 1111 1111 1100 0000 0001

P&H 4.4

-500

P&H 4.7

In binary, it's 0111 1111 1111 1111 1111 1111 1111 1010
In decimal, it's 2^31-1-5 = 2,147,483,642.

P&H 4.8

CAFEFACE

P&H 3.1 

begin:  addi $t0, $zero, 0   #$t0 initialization. We will store here the sum of odd numbers not grater than n
        addi $t1, $zero, 1   #$t1 initialization. We will store here succesive odd values

loop:   slt $t2, $a0, $t1    # for (sum=0, odd=1; n>=odd; odd+2) {
        bne $t2, $zero, finish
        addi $t1, $t1, 2     # sum += odd
        j loop               # }

finish: add $v0, $to, $zero  # we copy the value in the output register

We are computing the sum of the odd numbers not greater than n. We store the result into $vo.

P&H 3.4

The solution is simple:
addi $t0,$t1,100

P&H 3.5

	lui	$t1, 0x003d
	ori	$t1, 0x900
	lw	$t2, 44($t1)
	add	$t2, $t2, $t0
	sw	$t2, 40($t1)

4,000,000 base 10 is 003d0900 base 16.

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