Answer:
- 2864
Step-by-step explanation:
Given that,
The number is of 4 digits
All are different
The sum of the 4 digits = 20
Hundred's digit is twice than one's digit
A.T.Q.
Let the unit digit be 4. So, the hundred's digit would be 4 * 2 = 8
Now, we have
_8_4
We know that the sum of four digits is 20. Thus,
_ + 8 + _ + 4 = 20
∵ _ + _ = 20 - 12 = 8
The possible numbers must make a sum of 8. Thus, one possibility can be 2 and 6.
Therefore, the number can be
2864
( 2 + 8 + 6 + 4 = 20)
Step-by-step explanation:
Old Railroad Car:
- 1 day of coal in 15 hours
- 1/15 days of coal in 1 hour
New Railroad Car:
- 1 day of coal in 10 hours
- 1/10 days of coal in 1 hour
Total number of days of coal in 1 hour
= 1/15 + 1/10 = 1/6.
Since there is 1/6 days of coal in 1 hour,
there will be 1 day of coal in 6 hours.
It will take them 6 hours to transport the supply.
Answer:
74 cars
Step-by-step explanation:
14(2) + 4x = 324
28 + 4x = 324
4x = 296
x = 74
Answer:
<em>Arielle has 374 grasshoppers and 187 crickets</em>
Step-by-step explanation:
Let's set:
x = number of grasshoppers
y = number of crickets
Arielle has a collection of 561 insects, thus:
x + y = 561 [1]
The number of grasshoppers is twice the number of crickets, thus:
x = 2y [2]
Substituting [2] in [1]:
2y + y = 561
Simplifying:
3y = 561
Dividing by 3:
y = 561/3
y = 187
From [2]:
x = 2*187 = 374
x = 374
Arielle has 374 grasshoppers and 187 crickets
