What is the value of the expression?
3 1/8 divided by 1 5/8
A. 4 3/4
B. 3 1/5
C. 1 12/13
D. 1 1/2
Find the number that completes the equation.
2/7 divided by ___ = 2/21
A. 2/7
B. 1/3
C. 3
D. 21/2
2 answers
B. 1/3
A.
3 1/8 = 3 + 1 / 8 = 24 / 8 + 1 / 8 = 25 / 8
1 5/8 = 1 + 5 / 8 = 8 / 8 + 5 / 8 = 13 / 8
3 1/8 / 1 5/8 = ( 25 / 8 ) / ( 13 / 8 ) = 25 • 8 / 8 • 13 =
25 / 12 = ( 13 + 12 ) / 13 =
13 / 13 + 12 / 13 = 1 + 12 / 13 =
1 12/13
B.
( 2 / 7 ) / x = 2 / 7
Now:
( 2 / 7 ) / x = 2 / 21
2 / 7 x = 2 / 21
Cross multiply.
2 • 21 = 7 x • 2
42 = 14 x
14 x = 42
x = 42 / 14 = 3
2/7 divided by 3 = 2/21
3 1/8 = 3 + 1 / 8 = 24 / 8 + 1 / 8 = 25 / 8
1 5/8 = 1 + 5 / 8 = 8 / 8 + 5 / 8 = 13 / 8
3 1/8 / 1 5/8 = ( 25 / 8 ) / ( 13 / 8 ) = 25 • 8 / 8 • 13 =
25 / 12 = ( 13 + 12 ) / 13 =
13 / 13 + 12 / 13 = 1 + 12 / 13 =
1 12/13
B.
( 2 / 7 ) / x = 2 / 7
Now:
( 2 / 7 ) / x = 2 / 21
2 / 7 x = 2 / 21
Cross multiply.
2 • 21 = 7 x • 2
42 = 14 x
14 x = 42
x = 42 / 14 = 3
2/7 divided by 3 = 2/21