A crane has a cable with a breaking strain of 6400 kg
measured to 2 significant figures.
It is used to lift crates which weigh 90 kg measured to the nearest 10 kg.
What is the greatest number of crates that can safely be lifted
at one time without breaking the cable?

The greatest number that can be safely lifted is 71 crates.

Step-by-step explanation: The crane has been described as having a breaking strain of 6400 kg (approximately). This implies that once the total capacity of crates lifted reaches the 6400 kg mark, the cable has a tendency to break. However it can lift crates which has an individual weight of 90 kg.

To find the maximum number of 90 kg crates that can be lifted at once we shall divide 6400 kg by 90 kg

Max No of crates = 6400/90

Max No of crates = 71.1111

Note however that the crates cannot be in fractions, hence the result shall be rounded to the nearest whole number.

Therefore, the greatest number of crates that can lifted without breaking the cable is 71 crates

**A quick check shows that 71 x 90 kg = 6,390 kg**

4x and 6y

im not sure though

trapezoid

step-by-step explanation:

first i plotted all my points on a grid graph

i made sure all of them were in the correct quadrant

then i saw it was a trapezoid or a quadrilateral