Step-by-step answer:
Answer to problems of this kind is the reciprocal of the harmonic mean of the time required.
We need to find the average of the speeds, not the average of the time.
The respective speeds are 1/3 and 1/4.
The average of the speeds is therefore (1/3+1/4)/2 = 7/24 (harmonic mean of the time taken).
The time required is therefore the reciprocal of the unit speed,
T = 1/(7/24) = 24/7 = 3 3/7 minutes, or approximately 3.43 minutes.
Then try your best and reach your limit
Answer: C) Cannot be done
Taking the square root of a negative number is not possible unless you involve complex numbers. If your teacher has not introduced that topic yet, then you just simply say "cannot be done" or something along those lines.
Answer:the price now is $128
Step-by-step explanation:
you can get this by dividing the cost by the percentage it has risen by. For example: 120 / 15 = 8 and then you add 8 to the initial price