Taran sold 30 milkshakes while working at Frozen Delights. 70% of the milkshakes were chocolate chip. The rest were chocolate. After Taran sold some more chocolate chip milkshakes, the percentage of chocolate milkshakes decreased to 25%. How many more chocolate chip milkshakes did Taran sell?

Guest Apr 6, 2021

#1**+1 **

Hint: Find the numbers of original chocolate chip and chocolate milkshakes. Then find the percentages of the numbers.

RiemannIntegralzzz Apr 6, 2021

#2**+1 **

30 * .70 = 21 were chocolate chip, 9 were chocolate

If the pct of chocolate milkshakes sold dipped to 25%, then 75% of the final totla must be chocolate chip

So

Let x be the nuber of additional chocolate chip milkshakes sold and we have that

[21 + x] / [ 30 + x] = .75 cross-multiply

21 + x = .75 [ 30 + x]

21 + x = 22.5 + .75x

x - .75x = 22.5 -21

.25x = 1.5

x = 1.5 / .25 = 6 = number of additional chocolate chip milkshakes sold

Proof : 30 + 6 = 36 in total were sold.....9 were chocolate....9 / 36 = 1/ 4 = 25%

CPhill Apr 6, 2021