Answer:
3 3/7 or 24/7 mins
Step-by-step explanation:
Let total job = X
Jeff's rate = X/6
Bob's rate = X/8
Combined rate = X/6 + X/8
(4X × 3X)/24 = 7X/24
7X/24 = X/T
T = X ÷ (7X/24)
T = X × (24/7X)
T = 24/7 mins
Shortcut:
T = product of individual times/sum of individual times
T = (6×8)/(6+8)
T = 48/14
T = 24/7
T = 3 3/7 mins
The two numbers are very near 7200 and 300. The sum of those is a good estimate of your sum:
... 7200 + 300 = 7500
_____
If you're taught methods of addition that include "make a ten" or "make a hundred", you know you can "borrow" a 1 from 7203 (making it 7202) and loan that 1 to 299 to make it 300. Now, you know your sum is exactly 7202+300 = 7502, with no estimation necessary.
Answer:
Step-by-step explanation:
We assume the given sum is the sum of interior angles of a triangle, so is equal to 180°.
48° +X +(X -44°) = 180°
2X +4° = 180° . . . . . . . . . . collect terms
X +2° = 90° . . . . . . . . . . . .divide by 2
X = 88° . . . . . . . . . . . . . . . subtract 2°
Then the other interior angle is ...
(X -44°) = 88° -44° = 44°
The unknown interior angles are ...
