Suppose that a rainbow fish can swim 60 feet in 6 seconds. An angelfish can swim 45
feet in 2 seconds.
Which fish can swim faster and by how much?
The angelfish swims 4.5 feet per second faster.
The angelfish swims 12.5 feet per second faster.
The rainbow fish swims 4.5 feet per second faster.
The rainbow fish swims 12.5 feet per second faster.

The angle fish swims 12.5 feet per second faster.

Step-by-step explanation:

First get the speed of the two fishes

Speed = distance/time

The rainbow fish can swim 60 feet in 6 secs

Speed = distance/time

= 60/6 = 10 feet per second

An angle fish can swim 45feet in 2 secs

Speed = 45/2

= 22.5 feet per second

Therefore, the angle fish swims faster .

Now subtract the speed of rainbow fish from that of the angle fish to get the speed with which it swims faster

22.5 - 10 = 12.5feet per second

step-by-step explanation:

30% of $420 is 0.30($420) = $126 and $420 + $126 = $546.

or, 130% of $420 is 1.3($420) = $546.

notice that this is not the $600 original list price with which we started.

why doesn't this work?

the method does not work because 30% of $420 is not the same amount as the 30% of $600. it may seem obvious when stated this way, but it is a very common error made on problems of this type. we cannot just use the same percent and get back to the original amount because we are taking that percent of a different value.

to work problems of this type correctly, it is generally best to write an equation for the situation and then solve.

example: since (100% – 30%)(original price) = (sale price)

70% of the   (original price) is $420.

0.7x   = 420

equation image indicator

x = 600

the original cost was $600.

we may also solve this problem using the two-step method. working the problem in two steps requires us to use more algebra skills. we have to know that x = 1x (identity property of multiplicationtext annotation indicator) and that 1x – 0.3x = 0.7x (subtracting like terms). then we solve the problem as follows:

(original price) – 30%(original price) = sale price

x – 0.3x = 420

0.7x = $420

equation image indicator

x = 600

the original cost was $600.  

note that with both of the above methods we do obtain the correct original amount.

example: after a 5% pay raise, hermione is earning $22,680 per year. what was she earning before the pay raise?

105% of (original salary) = current salary

1.05x = 22,680

equation image indicator

x = 21,600

hermione earned $21,600 per year before the pay raise.

this is an example so maybe you will get how to at least do it!

it shoild be o

step-by-step explanation: