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### Course: Operations and Algebraic Thinking 222-226>Unit 2

Lesson 6: Two-step equation word problems

# Equation word problem: super yoga (1 of 2)

Using information from the Super Yoga word problem, explore all the possible combinations and create equations which express the possibilities. Let's figure out which plan is best! Created by Sal Khan.

## Want to join the conversation?

• How would you account for when you hit the second month and an additional \$20 is spent?
• I guess you could modify your equation to include a second variable (let's make it 'M') that represents the number of months, thus:

C = 20*M + 8*S

This means that you also have to include another column to the table, 'M', which tells you in which month you currently are.
• Bruh I would just take the trial plan. You only pay 12 bucks. Why even get a membership it's not even anything extra.
• I did the math (I like to do try to do it before they explain it), and it seems that if you have a budget above \$60 or are going for more than 5 sessions a month, then the basic plan is more worth it (68 for 6 sessions for example). Anything less than \$60 OR less than 5 sessions, then the trial is worth it.

In this video, they solve for C (the total monthly cost). Using a formula of subject C can give you the total price given the amount of sessions you require. For example, the basic membership for 6 sessions would be:
C = 20 + 8s
C = 20 + 8(6)
C = \$68 per month for 6 sessions
And for the trial it would be:
C = 12s
C = 12(6)
C = \$72 for 6 sessions

However, if you care more about which one is cheaper for a certain budget limit (you don't care about number of sessions, you just want to know how much 's' sessions would cost), then you can switch the subject of the formula to 's'. In such case, the formula for basic membership would be:
s = (C-20)/8
and for trial, it would be:
s = C/12

For example, let's say you have a budget of \$45 (to spend on one month) but you don't know which one will give you more sessions, you just plug that \$50 where 'C' is and you get the total session count. In this case, it would be:
Basic membership:
s = (45-20)/8
s = 3.125 sessions
Trial:
s = 45/12
s = 3.75 sessions

Therefore, for the budget of \$45, trial wins out in terms of sessions you get.

Using either one of the 2 formulas, you can confirm my original statement. You will also note that 5 sessions is equal price between trial and membership, so in that case it wouldn't matter which one you choose.
• How many Sessions are per month though? If there is 1 each week he would only have to pay \$20 plus the \$8 for the sessions.
• I guess you just have to assume that a session is there whenever you want it.
• on every math test, I always be like aww man I wish I was Khan who else?
• Just like me, he has years of experience on you, so if you enjoy math and look back 10 years from now, you will say how easy this was looking back, but new things always take time to learn. I am proof that you can still teach old dogs new tricks.
• Wait, how come you pay 20\$ even if you don't attend? That makes no sense whatsoever. So basically if you get the Basic Plan your literately negative 20\$😕🤯😔🤷?
• Assuming that you are thinking about attending, you are correct, if you never go, there is no use buying the basic plan. If you attend less than 5 times, then you are best off with the trial plan. At 5 times, each plan costs the same, and if you attend more than 5 times, you are better off with the basic plan. This happens all the time in real life, people make a new years resolution to get fit and join a club, but within a few months, they are paying and not always going.
• Why would you have to pay an addition of \$8 if you already have the monthly plan of \$20
• The monthly plan simply gives you a \$4 discount per session(when compared to the trial plan).
(1 vote)
• This is how I do this in my head: I need to make up the \$20 extra for the monthly plan in savings to make it worth it. The savings is made through the difference in per-sessions cost, which is \$4 (\$12 - \$8). So how many sessions does it take until I've absorbed the \$20 fee (how many times does 4 go into 20)? 5. So I know that the cost equals out at 5 sessions, and beyond that, monthly plan is better. Thoughts? Maybe I'm missing the point?
• That's right, actually. At 5 sessions in a month, both the Trial Plan and the Basic Plan cost \$60. However, if you attend 6 sessions in a month, the Trial Plan will cost \$72 and the Basic Plan will cost only \$68.
(1 vote)
• i did not understand at all