Johnny spend 1/7 of his income on food, 1/10 of his income on gas, and 3/8 of his income on rent. what percentage of his income remains after he has paid for food, gas, and rent?

  38.2%

Step-by-step explanation:

1/7 ≈ 14.29%

1/10 = 10.00%

3/8 = 37.50%

The total that Johnny has allocated for food, gas, and rent is ...

  14.29% + 10.00% + 37.50% = 61.79%

So, the remaining amount is ...

  100% -61.79% = 38.21%

About 38.2% of Johnny's income remains.

answer: it's d

step-by-step explanation:

answer: 204

step-by-step explanation:

we are told that the revenue is

x⋅(4080−10x)=−10x^2+4080x

this is a quadratic function, so to maximize it we should find the x-value of its vertex. recall that the x-value of the vertex of the parabola ax^2+bx+c is given by the formula −b/2a.

so in this case, we have a=−10 and b=4080, so the x-value of the vertex is

−b/2a= −(4080)/2(−10)=204