Word Problems Flashcards
What is the formulas for Rate, Time and Distance
What must you convert before you answer Distance, Rate and Time questions
Know the common units conversions and change units so all the units in the question are consistent.
Example : If the rate is in MPH units , but you at given information like “it took Jeff 45 minutes”, then you must convert the 45 mins to hours. 45/60 = 0.75hrs or 3/4
What mustn’t you do when calculating Average speed questions?
You must not add the speed values together to get the average speed, for example don’t do 18mph + 6mph as it doesn’t give you average speed.
The correct method is : workout total time and total distance separately and then apply the average speed formula to get average speed
What is the Formulas for Total distance, Total time and Average speed
Total Distance = D1 + D2 + etc
Total Time = T1 + T2 + etc
Average speed = Total Distance/Total time
A . How would you solve multiple traveler, multiple trips or a trip with multiple legs question
B. What must you do when you have two unknowns in multiple traveler, trip, legs questions.
How would you solve questions when things are heading in same or opposite direction
Identify whether the following cases are going in same or opposite direction and if they are expanding or shrinking
1 and 2 are opposite directions so add speeds
3 and 4 are same direction so subtract speeds
A. How would you solve work rate questions
B. Can you add times with other times in a Work rate question, can you add rates with other rates
C. Times and rates are what of each other?
A. As you cannot add times together with other times, you must convert times into rates by reciprocal. Then find combined rate by adding rates like 1/15 + 1/0 = 1/6. Once you have combined rate flip it to get you the time so 1/6 = 6 hours/mins
B. You can’t add times with other times but you can add rates with other rates
C. Times and rates are reciprocal of each other
Use concentration formula
Answer = 64
Formula - Total concentrate/Total Volume
Step 1.
Total Concentration = 160 + 8x/100
Total concentration = 12 (4 + 8)
Step 2.
(160+8x/100) /12 = 56/100 and then simplify
Step 3. Solve and find x = 64
How would you solve weighted average or mixture problems
See example below
In this question, which variable should you pick to multiply with all the values and why?
Right now twice Garry’s age is 1 more than 3 times Michael’s age. In 4 years time, 2 times Michael’s age will be 10 more than Garry’s age. If G is Garry’s current age, and M is Micheal current age. Which expression below signifies this relationship?
Answer - 2G = 3M + 1
2(M + 4) = (G+4)+ 10
