A grocer has 18kg of black tea worth 3.5per kg. She wants to mix

The question is incomplete, the complete question is;

A grocer has 18 kg of black tea worth $3.5 per kg. She wants to mix it with green tea worth $2.6 per kg to sell the mixture at $2.9 per kg. How much of green tea should she use?

36

Step-by-step explanation:

Let the weight of the green tea used be x kg.

From the question:

We have:

18 kg of black tea at $ 3.5 per kg. Thus total cost of black tea is 18 x 3.5 = $ 63

Cost of green tea is $2.6 per kg. Total cost of green tea is 2.6 * x = $2.6x

Total weight of the mixture is 18 + x kg.

Total cost of the mixture is = $2.9 (18 + x)

Thus,

Total cost of black tea + total cost of green tea = Total cost of the mixture

$63 + $2.6 x = $2.9 (18 + x)

$63 + $2.6x = $52.2 + $2.9x

63 – 52.2 = 0.3 x

10.8 = 0.3 x

x = 10.8/0.3

x = 36

36 kg of green tea is needed