Question

Two groups of staff at a store are making flowers to decorate the entrance. If Group A were to do it alone, it would take them 10 hours to complete the task. If Group B were to do it alone it would take them 15 hours. The groups decided to work together. Group B took a break for 1 hour and 40 minutes. Group A ended up making 300 more flowers than Group B. HOW MANY FLOWERS ARE THERE ALTOGETHER?

Answer 1

Answer:

$\dfrac{6750}{7}$

Step-by-step explanation:

Let x be the number of flowers. If Group A were to make x flowers alone, it would take them 10 hours to complete the task, then they make $\dfrac{x}{10}$ flowers in an hour.  If Group B were to make x flowers alone, it would take them 15 hours to complete the task, then they make $\dfrac{x}{15}$ flowers in an hour.

The groups decided to work together. They can make $\dfrac{x}{10}+\dfrac{x}{15}=\dfrac{x}{6}$ together in an hour and it takes them $\dfrac{x}{\frac{x}{6}}=6$ hours. Group B took a break for 1 hour and 40 minutes ($1\dfrac{2}{3}$ hour), then Group B works

$6-1\dfrac{2}{3}=4\dfrac{1}{3}$ hours.

Thus,

$\dfrac{x}{10}\cdot 6-\dfrac{x}{15}\cdot 4\dfrac{1}{3}=300,\\ \\\dfrac{3x}{5}-\dfrac{13x}{45}=300,\\ \\14x=300\cdot 45=13500,\\ \\x=\dfrac{13500}{14}=\dfrac{6750}{7}.$