The fill pipe for a tank can fill the tank in 15 min and the drain pipe can empty the tank in 10 min. If both pipes are accidentally opened, how long will it take to empty the full tank?

30 min

Step-by-step explanation:

The tank can be filled in 15 min, this means that in one min, 1/15 of the tank can be filled.

The tank can be emptied in 10 min, this means that in one min, 1/10 of the tank can be emptied.

the outflow rate - the inflow rate = rate of emptying the tank

1/10 - 1/15 = 1/x

where x is the time it will take to empty the tank

solving, we'll have

1/30 = 1/x

the reciprocal of the equation gives

x = 30 min

the length of o'p' is .

step-by-step explanation:

it is given that the quadrilateral m'n'o'p' is the image of quadrilateral mnop after dilation.

the center of dilation is origin and the scale factor is 1.5.

in dilation the image and preimge are similar figures. it means the sides of image and preimage are proportional.

the scale factor is defined as

the scale factor is 1.5.

multiply both sides by op.

note: if the value of op is given, then multiply the value of op with 1.5 to get the length of side o'p'.

therefore length of o'p' is .

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.