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If (64)^2 - (36)^2 = 20 k then the valu...

If `(64)^2 - (36)^2 = 20 k` then the value of k is :

A

140

B

120

C

80

D

none of these

Text Solution

Verified by Experts

The correct Answer is:
A
`(64)^2-(36)^2=20k`
`rarr(64+36)(64-36)=20k`
`rarr 100.28=20k`
`rarr 20xx5xx28=20k`
`rarr k=28xx5=140`
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