Introduce variables to represent items of interest in the problem. For example,

Question

Introduce variables to represent items of interest in the problem. For

example, (1) Let n be the number to be found, or (2) Let a be Alice’s

current age, or (3) Let r be the rate of the first car.

(2)

Write down an equation using the information given in the problem. This

is the really important part for this particular assignment!

(3)

Solve the equation and find the value requested in the problem.

The distance between A and B is 180 miles. An automobile at A starts for B are the rate of 40 miles per hour at the same time that an automobile at B starts for A at the rate of 50 miles per

hour. How long will it be before the automobiles meet?

A snail leaves A and travels at the rate of four inches per minute to B. At B the snail catches a ride on a turtle and is carried back the A at the rate of ten inches per minute. If the round trip takes 14 minutes, what is the distance between A and B?

Two boats start at the same point, one goes straight north, the

other straight south. The first boat travels twice as fast as the

second. After three hours they are 72 miles apart. Find the rate

of the faster boat.

Explanation / Answer

The distance between A and B is 180 miles. An automobile at A starts for B are the rate of 40 miles per hour at the same time that an automobile at B starts for A at the rate of 50 miles per
hour. How long will it be before the automobiles meet?

Soln :
Time be 't'

Distance covered by vehicle moving from A to B is :
speed * time
d1 = 40*t = 40t miles

Similarly d2 = 50t miles

40t + 50t = 180

90t = 180

t = 2

2 hrs ---> ANS

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A snail leaves A and travels at the rate of four inches per minute to B. At B the snail catches a ride on a turtle and is carried back the A at the rate of ten inches per minute. If the round trip takes 14 minutes, what is the distance between A and B?

Let distance be x

Time = distance/speed

Onward time = x/4
Return time = x/10

x/4 + x/10 = 14

14x/40 = 14

x = 40

So, 40 inches -----> ANS

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