<span>A rope weighs 400 grams per meter of length.
length=6.3m
400*6.3=2520g
2520g=2520/1000kg=2.52kg
The answer is D.</span>
3^2
Here’s the working out;
Let x be the amount he invests at 6%
1280 = 0.06x + 0.07(20000 - x)
1280 = 0.06x + 1400 - 0.07x
1280 - 1400 = -0.01x
-120 / -0.01 = x
x = 12000
Therefore, he invests $12,000 at 6% and $8,000 at 7%
