Question

If 2 over 7 of a ton of concrete covers 7 over 8 of a wall, how many tons of concrete are required to cover the entire wall?
A. 1/4 ton
B. 16/49 ton
C. 5/7 ton
D. 65/56 tons

Answer 1

@jcoury

Answer 2

\[\frac{ 1~wall }{ 1 }*\frac{ 2/7 ~ ton }{ 7/8~wall } = ~~~ton\]

Answer 3

cross multiply

Answer 4

no, just calculate

Answer 5

How?

Answer 6

oh,

to divide a fraction by a fraction, flip the bottom one over and multiply them

Answer 7

\[\frac{ 2/7 }{ 7/8 } = \frac{ 2 }{ 7 }*\frac{ 8 }{ 7 }\]

Answer 8

So what do I do?

Answer 9

multiply

\[\frac{ 2/7 }{ 7/8 } = \frac{ 2 }{ 7 }*\frac{ 8 }{ 7 }=\frac{ 8*2 }{ 7*7 } = \]

Answer 10

Huh?

Answer 11

Dividing Fractions -
\[\frac{ \frac{ a }{ b } }{ \frac{ c }{ d } } = \frac{ a }{ b }*\frac{ d }{ c }\]

Answer 12

multiplying fractions -
\[\frac{ a }{ b }*\frac{ c }{ d } = \frac{ a*c }{ b*d }\]

Answer 13

so your final answer is (8*2) / (7*7) tons