Quantitative Aptitude
SURDS AND INDICES MCQs
Surds & Indices, Indices And Surds, Power
`(1000)^7 -: 10^18` = `(1000)^7/10^18` = `(10^3)^7/10^18` = `10^((3 xx 7))/(10^18)`
=`10^21/10^18` = `(10)^(21 - 18)` = `10^3` = 1000
`(1/216)^(- (2)/(3)) -: (1/27)^(- (4)/(3)) ` = `(216)^(2/3) -: (27)^(4/3)` = `((216)^(2/3))/((27)^(4/3))`
= `((6^3)^(2/3))/((3^3)^(4/3)` = `(6^((3 xx 2/3)))/(3^((3 xx 4/3)))` = `(6^2)/(3^4)`= `36/81` = `4/9`
`(2.4 xx 10^3) -: (8 xx 10^-2)`= `(2.4 xx 10^3)/(8 xx 10^-2)` = `(24 xx 10^2)/(8 xx 10^-2)` = `(3 xx 10^4)`
` (10)^150 -: (10)^146` = `((10)^150)/((10)^146)` = `(10)^(150 - 146)` = `10^4` = 10000
`(1)/((216)^(- 2/3)) + (1)/((256)^(- 3/4)) +(1)/((32)^(- 1/5)) `
=`(1)/( (6^3)^( - 2/3)) + (1)/( (4^4)^( - 3/4)) + (1)/( (2^5)^( - 1/5)`
= `(1)/6^(3 xx ( - 2)/3) +(1)/4^(4 xx ( - 3)/4) +(1)/2^(5 xx (- 1)/5) `
=`(1)/(6)^-2 + (1)/(4)^-3 + (1)/(2)^-1`= `(6^2 + 4^3 +2^1)` = (36 +64 + 2) = 102.
`5^(1/4) xx (125)^0.25` =` 5^0.25 xx (5^3)^0.25` = ` 5^0.25 xx 5^(3 xx 0.25)` = `5^0.25 xx 5^0.75`
= `5^((0.25 + 0.75))` = `5^1` = 5.
`( - 1/216)^( - (2)/(3)) `=` [( - 1/6)^3] ^(- (2)/(3)` = `(- 1/6)^(3 xx((-2))/(3))` = `(- 1/6)^ - 2`
= `1/(- 1/6)^2` = `1/(1/36)` = 36.
`(32/243)^(- (4)/(5))` = `{(2/3)^5}^( - (4)/(5))` = `((2)/(3))^(5 xx ((- 4))/(5))` = `((2)/(3))^(- 4)`
= `(3/2)^4` =`(3^4)/(2^4)`= `81/16`
`(sqrt(8))^((1)/(3))` = `(8^(1/2))^((1)/(3))` = `8^((1/2 xx 1/3))` = ` 8 ^((1)/( 6))` = `(2^3)^((1)/(6))`
= `2^((3 xx 1/6))` = `2^(1/2)` = `sqrt(2)`
`(256)^((5)/(4))` = `(4^4)^((5)/(4))` = `4^((4 xx 5/4))` = `4^5` = 1024.