A) If Ksh. 1 = 0.007524, how many Kenyan shillings make 1? b) X c) The scale of a map is 1cm: 52500m. How many cm on the map represent 1m on the ground? d) Machine A can complete a task in 8 hours, Ma

Given that Ksh. 1 is equal to 0.007524 US Dollars. To find how many Kenyan shillings make 1 US dollar, we need to find the reciprocal of the given rate.

$$1 \text{ US dollar} = \frac{1}{0.007524} \text{ Ksh}$$ $$1 \text{ US dollar} \approx 132.9079 \text{ Ksh}$$

Rounding to two decimal places:

$$1 \text{ US dollar} \approx 132.91 \text{ Ksh}$$

Therefore, $\boxed{132.91 \text{ Kenyan shillings}}$ make 1 US dollar.

Given that 1 cm on the drawing represents 52500 m on the ground. We need to find how many cm are equivalent to 1 m.
The scale is:

$$1 \text{ cm} \equiv 52500 \text{ m}$$

To find the equivalent of 1 m in cm, divide both sides by 52500:

$$\frac{1}{52500} \text{ cm} \equiv \frac{52500}{52500} \text{ m}$$ $$\frac{1}{52500} \text{ cm} \equiv 1 \text{ m}$$

As a decimal:

$$\frac{1}{52500} \approx 0.0000190476 \text{ cm}$$

Rounding to a reasonable number of significant figures, or leaving as a fraction:

$$1 \text{ m} \equiv \boxed{\frac{1}{52500} \text{ cm}}$$

Let the total task be 1 unit of work.

• Machine A takes 8 hours, so its work rate ($R_A$) is $\frac{1}{8}$ task/hour.
• Machine B takes 10 hours, so its work rate ($R_B$) is $\frac{1}{10}$ task/hour.
• Machine A and C working together take 5 hours, so their combined work rate ($R_{A+C}$) is $\frac{1}{5}$ task/hour.

First, find the work rate of Machine C ($R_C$):

$$R_{A+C} = R_A + R_C$$ $$\frac{1}{5} = \frac{1}{8} + R_C$$ $$R_C = \frac{1}{5} - \frac{1}{8}$$

To subtract, find a common denominator, which is 40:

$$R_C = \frac{8}{40} - \frac{5}{40}$$ $$R_C = \frac{3}{40} \text{ task/hour}$$

Next, find the combined work rate of Machine B and Machine C ($R_{B+C}$):

$$R_{B+C} = R_B + R_C$$ $$R_{B+C} = \frac{1}{10} + \frac{3}{40}$$

To add, find a common denominator, which is 40:

$$R_{B+C} = \frac{4}{40} + \frac{3}{40}$$ $$R_{B+C} = \frac{7}{40} \text{ task/hour}$$

Finally, determine the time it would take Machine B and Machine C working together ($T_{B+C}$):

$$T_{B+C} = \frac{1}{R_{B+C}}$$ $$T_{B+C} = \frac{1}{\frac{7}{40}}$$ $$T_{B+C} = \frac{40}{7} \text{ hours}$$

As a mixed number:

$$T_{B+C} = 5 \frac{5}{7} \text{ hours}$$

The time it would take Machine B and Machine C working together is $\boxed{\frac{40}{7} \text{ hours}}$ or $\boxed{5 \frac{5}{7} \text{ hours}}$.