How many strawberries are in Emma’s smoothie?

Question

In a strawberry and banana smoothie the number of bananas is one sixth the number of strawberries, minus one. Emma’s smoothie contains 2 bananas and s strawberries.  How many strawberries are in Emma’s smoothie?

Answer 1

OK, here's the setup:

We relate bananas to strawberries as written above, as b = 1/6 * s - 1 which is s/6 - 1

 

Set variables:  you need one variable to solve one equation so we look for a variable to drop away.

 

strawberries = s,   bananas = b = s/6 - 1 

She uses 2 bananas in her smoothie so replace b with 2, now 2 = s/6 - 1 (notice 'b' dropped away - yippee!) and you can now solve for s and check for b.   Add 1 to both sides to get: 3=s/6, then multiply by 6 to get s=18   18 strawberries.  ok check b from the equation for bananas, b = 18/6 - 1 , b = 3-1 = 2 check!  She uses 2 bananas and 18 delicious strawberries in her healthy smoothie.  Try one!