HElp ASAP A cement truck mixes 1 part cement
with 4 parts sand. If 2.5 cubic yards of
cement are used, how much sand is
needed for the mixture?
a. 6.25 cubic yards
b. 7.5 cubic yards
c. 10 cubic yards
d. 12.5 cubic yards

What is the maximum total area that 450cm of string can enclose if it is used to form perimeters of two adjoining rectangles as shown?

How to solve a simultaneous equation involved with fractions?

2people are trying different phones to see which one has the better talk time. chatlong has an average of 18 hours with a standard deviation of 2 hours and talk-a-lot has an average of 20 hours with a standard deviation of 3. the two people who tested their phones both got 20 hours of use on their phones. for the z-scores i got 1 for the chatlong company and 0 for talk-a-lot. what is the percentile for each z-score?