7 hours 12 minutes
6 hours 46 minutes
6 hours 53 minutes
--------------------------sum
Total: 19 hours 111 minutes, which converts to (19 × 60) + 111 = 1140 + 111 = 1251 minutes
Calculate average time by dividing by 3: 1251 / 3 = 417 minutes, equivalent to 6 hours 57 minutes, which is the average delivery duration.
Answer:
Option 1 is valid, which entails 2 hours of walking and 12 hours of running.
Step-by-step explanation:
The equations provided are:
3w + 6r ≥ 36
3w + 6r ≤ 90
We'll assess which options comply with these equations.
1) 2 hours walking; 12 hours running
w = 2 and r = 12
3w + 6r ≥ 36
3(2) + 6(12) ≥ 36
6+72 ≥ 36
78 ≥ 36
3w + 6r ≤ 90
3(2) + 6(12) ≤ 90
6+72 ≤ 90
78 ≤ 90
Both equations are satisfied. Option 1 is valid.
2) 4 hours walking; 3 hours running
w = 4 and r = 3
3w + 6r ≥ 36
3(4) + 6(3) ≥ 36
12+18 ≥ 36
30 ≥ 36 (this does not hold since 30 < 36)
3w + 6r ≤ 90
3(4) + 6(3) ≤ 90
12+18 ≤ 90
30 ≤ 90
Thus, Option 2 is invalid.
3) 9 hours running; 12 hours walking
w = 9 and r = 12
3w + 6r ≥ 36
3(9) + 6(12) ≥ 36
27+72 ≥ 36
99 ≥ 36
3w + 6r ≤ 90
3(9) + 6(12) ≤ 90
27+72 ≤ 90
99 ≤ 90 (this does not hold since 99 > 90)
Option 3 is invalid.
4) 12 hours walking; 10 hours running
w = 12 and r = 10
3w + 6r ≥ 36
3(12) + 6(10) ≥ 36
36+60 ≥ 36
96 ≥ 36
3w + 6r ≤ 90
3(12) + 6(10) ≤ 90
36 + 60 ≤ 90
96 ≤ 90 (this does not hold since 96 > 90)
So, Option 4 is invalid.
Answer:
7 years
Step-by-step explanation:
Suri is 17 years old.
Her cousin's age is c.
Suri's age is stated to be 4 less than 3 times her cousin’s age.
This means we take 3 times her cousin’s age and subtract 4.
17 = 3c - 4
We now need to solve for c, which represents her cousin's age.
Add 4 to each side:
17 + 4 = 3c - 4 + 4
17 + 4 = 3c
21 = 3c
Now divide both sides by 3:
21/3 = 3c/3
7 = c
Thus,
Her cousin is 7 years old.
