Baker Jack baked 160 cakes. 55% of them were walnut cakes and the rest were almond cakes. After selling some of the walnut cakes, the percentage of the walnut cakes become 40%. How many cakes were left ?
With 55% of the 160 being walnut, .55(160) = 88 were walnut
Let the number of walnut sold be W
Then after selling W walnut cakes, he’s left with 88 - W walnut cakes
Since 40% of the remaining cakes were walnut - after W walnut cakes were sold - then we have:
.4(160 - W) = 88 - W ------- Cross-multiplying
64 - .4W = 88 - W
- .4W + W = 88 - 64
.6W = 24
Number of walnut cakes sold, or
Thus, 160 - 40 = 120 cakes, were left