Fokin wrote:Barbara invest $2400 in the national Bank at 5% How much additional money must she invest at 8 % so that total annual income will be equal to 6% of the entire investments ?
a) 3,600
b) 3,000
c) 2,400
d) 1,200
e) 1,000
now let say the additional amount invested be x
so total amount invested =2400+x
total income at the rate of 6 %= 6/100*(2400+x) = 144+3x/50
Barbara invest $2400 in the national Bank at 5%
so income annual=5/100*2400=120
now barbara invest the remaining x at 8 %
so annual income =8/100*x=2x/25
now return on $2400 in the national Bank at 5% +return on x at 8 %= return on totalinvestment(2400+x) at 6%
120+2x/25=144+3x/50
2x/25-3x/50=24
x/50=24
x=1200
so additional amount to be invested is 1200
Ideation without execution is delusion
