42. Carmen spends 5 minutes, correct to the nearest minute, preparing one meal. She spends a total time of T minutes preparing 30 meals. Between what limits does lie?
[2]

4.5 < T < 5.5

Step-by-step explanation:

Nearest 5 minutes could be 4.5 to 5.49

The computation of the limits in between is shown below:

Now Multiply these numbers by 30

4.5 × 30 = 135

5.4 × 30 = 162

5.5 × 30 = 165

We can easily round 5.5 would to 6, since we cannot use 5.5.  

Therefore  

135 < T < 162

Therefore If the correct answer is  135 < T < 165

So it must be 4.5 < T < 5.5

a) 15/7

step-by-step explanation:

step by step resolutions

1) n+n+1+n+2=51

3n+3=51

3n=48

n=16

the three numbers are 16, 17 and 18.

2) x+15=4x

3x=15

x=5

radha is now 5 years old

3) the two digits are x and y.

y=3x

(10x+y)+(10y+x)=88

y=3x

11x+11y=88

y=3x

x+y=8

x+3x=8

x=2

the original number can be either 28 or 82.

4) n+(n+2)+(n+4)=48

3n+6=48

3n=42

n=14

the numbers are 14, 16 and 18.

5) y=x+3

10y+x+10x+y=143

y=x+3

11x+11y=143

y=x+3

x+y=13

x+x+3=13

2x=10

x=5

the original number can be 57 or 75.

hope this !