Given that `P.e_(D) = (-)5` a consumer buys 10 kg at 5 per kg. find the new price if now he buys 20kg

Explanation

`{:(P" " 5),(P_(1)" "?),(overlineunderline(DeltaP" "?)):}" "{:(Q" "10),(Q_(1)" "20),(overlineunderline(DeltaQ" "10)):}`
`P.e_(D) = P/Qxx (DeltaQ)/(DeltaP)`
`-5= 5/10xx10/(DeltaP) or Delta=-1`
` DeltaP = P_(1)-P or -1 = P_(1)-5`
`-1+5=P_(1) or P_(1)=₹4`