Orange juice, a raisin bagel, and a cup of coffee from Kelly's Koffee Kart cost a total of $2.40. Kelly posts a notice announcing that, effective the following week, the price of orange juice will increase 50% and the price of bagels will increase 20%. After the increase, the same purchase will cost a total of $3.00, and the orange juice will cost twice as much as coffee. Find the price of each item before the increase.

orange juice 0.80 dollar

Bagel 1 dollar

coffe 0.60 dollar

Explanation:

We construct the equation system:

We subtract one from another to get an expression without C:

1.5A+1.2B+C - (A+B+C) = 3   -  2.40

0.5A + 0.2B  = 0.6

Then, we solve in the first part to express B as an expression of A

considering the coffe is worth half of the new cost of A

C = 1.5A / 2 = 0.75A

A + B + C = 2.40

A + B + 0.75A = 2.40

B = 2.40 - 1.75A

And now we replace in the other expression to get A:

0.5A + 0.2(2.40 - 1.75A) = 0.6

0.5A - 0.35A + 0.48 = 0.60

0.15A = 0.12

A = 0.12/0.15 = 0.8

Now we solve for C:

C = 0.75A = 0.6

Last, for B:

A + B + C = 2.40

0.8 + B + 0.6 = 2.40

B = 2.40 - 0.8 - 0.6 = 1

ans.

heterothermic organisms include those organisms that can switch between homeothermic (having body temperature higher than environment) and poikilothermic (having variation in internal body temperature) strategies.

some migratory birds show heterothermy as they decrease their metabolic rate during cold nights to keep their body temperature low. drop in metabolic rate allows increase in production efficiency of birds that reduces the internal body temperature to make it equal to external cold temperature during cold nights.

thus, the correct answer is 'birds allow their temperature drop in order to increase their production efficiency.'