A teacher gave her class two exams; 60% of the class passed the second exam, but only 48% of the
class passed both exams. What percent of those who passed the second exam also passed the first
exam?

80%

Step-by-step explanation:

If someone passed both, then they must have passed the second one.  This means that 48% that passed both is part of the 60% that passed the second.

If you think of it as a venn diagram, one circle would represent al that passed the first test, the other circle would be all that passed the second and the middle would be all that passed both.

Lets pretend we are using actual amounts rather than percents.  so 60 students passed the second test and 48 passed both.  that 48 is part of that 60, or more specifically, everyone in that 48 is also in the 60.  So the question is asking what is the percent of the 60 that passed the second  that is in the intersection.

I hope this helped in the understanding, but basically it is asking what percent of 60 is 48?  or if 60 is 100% what is 48.  Super simple way to find out is 48/60 = .8 or 80%

constant acceleration- a

constant velocity- c

no velocity or acceleration- b

explanation:

for body moving with a constant acceleration, the rate of change of displacement changes over time. this is proven by the increasing gradient of the curve (a) against time.

a body that is moving at constant velocity covers equal distances over equal periods of time, thus the straight line with a constant gradient c.

a stationary body   covers no displacement as time elapses. thus the flat line with   zero gradient.