This problem involves lists made from the letters T, H, E, O, R, Y, with repetition allowed. (a) How many 4-letter lists are there that don’t begin with T, or don’t end in Y? (b) How many 4-letter lists are there in which the sequence of letters T, H, E appears consecutively (in that order)? (c) How many 6-letter lists are there in which the sequence of letters T, H, E appears consecutively (in that order)?

Step-by-step explanation:

a.Consider A- 4 letter list don't begin with T & B-4 letter list don't end with Y

=5×6×6×6=1080

=6×6×6×5=1080

=5×6×6×5=900

=1080+1080-900=1260

b.=12

c.=216+216=432

yes because there is exactly one y value for every x value

for function there can't be more than one value for every x value

answer: c, the green line

step-by-step explanation:

there is no black line, eliminate b.

simple interest implies periodic payments, but the red line shows no payments, eliminate d.

simple interest has equal payments. if paid say every day, the graph is about a straight line (actually a stairstep).

the yellow line is not straight, eliminate a.

check: the green line is straight, answer is c.

simple interest with positive interest rate gives a straight line sloping up to the right. green line:

g(t) = $100 + ($200-$100) ÷ (20 years) × (t years)

= $100 + (4%/year) × ($100)(t years)

incidentally, the yellow line curving upward represents continuously compounded interest

y = $100 × 2^(t years / (14 assuming the yellow line hits $200 at 14 years. 2^0 is 1, so y(0) = $100; 2^(14/14) is 2, so y(14) = $200.