Answer:
180.07 rev / min
Step-by-step explanation:
Diameter (D) of each wheel =28 inches
Circumference (C) = π x 28 = 28π inches
Conversions:
1 mile = 63,360 inches
1 hour = 60 min
Hence 15 miles / hour
= (15)(63,360) inches / hour
= (15)(63,360) / 60 inches / min
= 15,840 inches per min
Number of revolutions per min = Number of inches per min ÷ circumference in inches
=15,840 inches/min ÷ 28π inches
= 180.07 revolutions per min
I like to use an X diagram to solve problems like this. The constituent percentages are on the left, the desired mix is in the middle and the numbers on the diagonals are the difference between the mix and the constituent.
The numbers 6 and 24 here represent the ratio of 40% to 10% chocolate. That 6:24 ratio can be reduced to 1:4. The sum of those ratio units is 1+4 = 5, so each must represent (200 kg)/5 = 40 kg of chocolate.
The mix must consist of
40 kg of 40% fat chocolate 160 kg of 10% fat chocolate
Multiplication and distributive property are your friends for this problen
The additive inverse of a number is the opposite number......for this problem, it is a number, that when added to -4 1/4 = 0.
so the additive inverse of -4 1/4 = 4 1/4