All categories

3 years ago

Charlie runs 2 laps in 8 minutes. How many minutes will 9 laps take him?

Mathematics

1 answer:

Fofino [41]3 years ago

8 0

Answer:

36 minutes

Step-by-step explanation:

We can write a ratio

2 laps 9 laps

------------- = --------------

8 minutes x minutes

Using cross products

2x = 8*9

2x = 72

Divide by 2

2x/2 = 72/2

x = 36 minutes

You might be interested in

17. A hemisphere of lead of radius 7 cm is cast into a right circular cone of height 49 cm. Find

Pavlova-9 [17]

Answer:

$r = 3.74cm$

Step-by-step explanation:

Given

Hemisphere

$Radius = 7cm$

Cone

$Height = 49m$

Required

Determine the radius of the cone

First, we calculate the volume (V1) of the hemisphere.

$V_1 = \frac{2}{3}\pi r^3$

Substitute 7 for r

$V_1 = \frac{2}{3}\pi * 7^3$

$V_1 = \frac{2}{3}\pi * 343$

$V_1 = \frac{686}{3}\pi$

Volume (V2) of a cone is:

$V_2 = \frac{1}{3}\pi r^2h$

Because the lead is cast into a cone, then they have the same volume.

So, we have:

$\frac{686}{3}\pi = \frac{1}{3}\pi r^2h$

$686 = r^2h$

Substitute 49 for h

$686 = r^2 * 49$

Divide both sides by 49

$r^2 = \frac{686}{49}$

$r^2 = 14$

$r = \sqrt{14$

$r = 3.74cm$

Hence, the radius of the cone is 3.74cm

5 0

3 years ago

Amy has a bowl of cereal for breakfast. the amount of cereal in the box (y) is determined by the number of days (x) that have pa

kogti [31]

Answer:

d=[0,12]

Step-by-step explanation:

6 0

3 years ago

Find the 12th term of each sequence. a9= 120, a14=195

Luda [366]

The general formula for an Arithmetic Progression is :

$\boxed {\boxed {T_n = a_1 + (n-1)d}}$

$\text {Given that } a_9 = 120,$

$T_9 = a_1 + (9 - 1)d = 120$

$a_1 + 8d = 120 \text { ------------------(1)}$

$\text {Given that } a_{14} = 195,$

$T_9 = a_1 + (14 - 1)d = 195$

$a_1 + 13d = 195 \text { ------------------(2)}$

Equation (2) - Equation (1) :

$13d - 8d = 195 - 120$

$5d = 75$

$d = 15$

Substitute d = 15 into Equation (1) :

$a_1 + 8(15) = 120$

$a_1 = 120 - 120$

$a_1 = 0$

$\text {Substitute }a_1 = 0 \text{ and d = } 15,$

$\boxed { \boxed { T_n = 15(n -1) }}$

Find 12th term :

$T_{12} = 15(12 -1) = 165$

$\boxed {\boxed {\text {Answer: The 12th term is 165.}}}$

7 0

3 years ago

Student #4:

elena-14-01-66 [18.8K]

Answer:

I can’t see the graph but this student solved it incorrectly. When she divide both sides by -2, she should’ve flipped the sign.

8 0

3 years ago

Read 2 more answers

What is the radius of a circle with a circumference of 15 cm

schepotkina [342]

Answer: The answer that I got is 2.39, i'm not fully sure if it is correct though.

Step-by-step explanation: First, you divide the circumference by pie, the you divide that answer by 2 to get the radius.

4 0

3 years ago