If z varies inversely as w, and z=10 when w=0.7, how do you find z when w=20?

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Answer 1 · 2016-06-25T13:24:20

When #w= 20, z = 0.35#

As per data provided :
#z=10 , # when #w =0.7#

As #z# is inversely proportional to #w:#

#color(blue)(z prop 1/w#

Introducing constant #k:#

# z = k xx 1/w#

# z = k/w#

# k = z xx w #

#k = 10 xx 0.7#

#color(blue)( k = 7#

Now, we are required to find #z# , when #w = 20.#

# z = k/w#

Substituting values for #k# and #w:#

# z = 7/20#

# z = 0.35#