Which student correctly describes how to use the count up method to add to 3.85 to find 8 -3.85?
Aryan
1. Add 5 hundredths.
2. Add 8 tenths
3. Add 4 ones
Nikhil
1. Add 5 hundredths.
2. Add 2 tenths
3. Add 4 ones
The difference is 4.25
The difference is 85.
Talia
1. Add 5 hundredths.
2. Add 1 tenth
3. Add 4 ones
Zohar
1. Add 1 hundredth
2. Add 5 tenths
3 Add 4 ones
The difference is 4.15
The difference
Aryan
Nikhil
Talia
Zohar

Zohar correctly describes how to use the count up method

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.