A=8/9x15/16x24/25x35/36x48/49x63/64
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`3/4 xx 8/9 xx 15/16 xx 24/25 xx 35/36`
`= (3xx8xx15xx24xx35)/(4xx9xx16xx25xx36)`
`=(3xx4xx2xx5xx3xx4xx6xx7xx5)/(4xx3xx3xx4xx4xx5xx5xx6xx6)`
`=(2xx7)/(4xx6)`
`=(2xx7)/(2xx2xx6)`
`=7/12`
\(\dfrac{3}{4}\times\dfrac{8}{9}\times\dfrac{15}{16}\times\dfrac{24}{25}\times\dfrac{35}{36}\)
= \(\dfrac{3\times8\times15\times24\times35}{4\times9\times16\times25\times36}\)
= \(\dfrac{3\times\left(2\times4\text{}\text{}\right)\times\left(3\times5\right)\times\left(6\times4\right)\times\left(5\times7\right)}{4\times\left(3\times3\right)\times\left(4\times4\right)\times\left(5\times5\right)\times\left(6\times6\right)}\)
=\(\dfrac{2\text{}\text{}\times3\times6\times\left(5\times7\right)}{3\times4\times5\times\left(6\times6\right)}\)
=\(\dfrac{\text{}\text{}7}{2\times6}\)= \(\dfrac{7}{12}\)
\(\frac{1\cdot3}{2\cdot2}\cdot\frac{2\cdot4}{3\cdot3}\cdot\frac{3\cdot5}{4\cdot4}\cdot...\cdot\frac{99\cdot101}{100\cdot100}\)
\(\frac{1\cdot101}{2\cdot100}\)
\(\frac{101}{200}\)
\(\dfrac{8}{9}x\dfrac{15}{16}x\dfrac{24}{25}x...\dfrac{8099}{8100}\)
\(=\dfrac{2x4}{3x3}x\dfrac{3x5}{4x4}x\dfrac{4x6}{5x5}x...x\dfrac{89x91}{90x90}\)
\(=\dfrac{2x4x3x5x4x6x...x89x91}{3x3x4x4x5x5x...x90x90}\)
\(=\dfrac{2x91}{3x90}=\dfrac{91}{135}\)
`@` `\text {Ans}`
`\downarrow`
`(25 \times 35) \times 40`
`= 25 \times 40 \times 35`
`= 1000 \times 35`
`= 35000`
`Answer:`
\(A=\frac{8}{9}.\frac{15}{16}.\frac{24}{25}.\frac{35}{36}.\frac{48}{49}.\frac{63}{64}\)
\(=\frac{8.15.24.35.48.63}{9.16.25.36.49.64}\)
\(=\frac{2^3.3.5.2^3.3.5.7.2^4.3.3^2.7}{3^2.2^4.5^2.2^2.3^2.7^2.2^6}\)
\(=\frac{3}{2^2}\)
\(=\frac{3}{4}\)