Given that there were 30 bacteria present originally.
a=30
Also given that the number doubles every one hour.
After one hour the count =2×30=60
Since the count doubles every hour it forms a G.P. with r=2
a,ar,ar2........
The count at the end of 2nd hour=ar^2=30×2^2=120
The count at the end of 4th hour=ar^4=30×2^4=480
The count at the end of 8th hour=ar^8n=30×2^8=7680
etc.
The count at the end of n^th hour=ar^n=30×2^n
Also, the equation y=30*(2)^8/1 give the same result y= 7680
Answer:
Q7. 11.3 inches (3 s.f.)
Q8. 96.2 ft
Q9. 36.4cm
Step-by-step explanation:
Q7. Please see attached picture for full solution.
Q8. Let the length of a side of the square be x ft.
Applying Pythagoras' Theorem,
Thus, the perimeter of the square is
Q9. Equilateral triangles have 3 equal sides and each interior angle is 60°.
Since the perimeter of the equilateral triangle is 126cm,
length of each side= 126÷3 = 42 cm
The green line drawn in picture 3 is the altitude of the triangle.
Let the altitude of the triangle be x cm.
sin 60°= 
(to 3 s.f.)
Therefore, the length of the altitude of the triangle is 36.4cm.
Each pair of interior angle and the exterior angle
So the exterior angle = 360° - the interior angle.
Answer:
The smaller number is 240.
Step-by-step explanation:
The question says that the larger number is 300, so 5 has to be 300.
4:5
?:300
You can use cross-multiplication or find the scale factor to find the answer.
Cross-multiplication:
4 × 300 ÷ 5 = 240
Finding the scale factor:
300 ÷ 5 = 60
4 × 60 = 240
The smaller number is 240.
15m is:
25% of 60m
500% of 3m
50% of 30m
1000% of 1.5m
