 
 <translate> Lizzy: Derek was 6 years old when he had three times as many dogs as cars. Ten years later, after selling some of his dogs and buying 210 more cars, the number of cars became twice the number of dogs. How many dogs does Derek have now if he had 90 dogs when he was six years old?.
Me: Hmmm, let me think. I think this is the detailed solution: <hau> Lizzy: Derek yana da shekaru 6 lokacin da yake da karnuka sau uku fiye da motoci. Shekaru goma bayan haka, ya sayar da wasu cikin karnukansa kuma ya sayi ƙarin motoci guda 210, adadin motocin ya ninka na karnukan sau biyu. Yaya karnuka nawa Derek ke da su yanzu idan yana da karnuka 90 lokacin yana da shekaru shida? Ni: Hmmm, bari in yi tunani. Ina ganin wannan shi ne cikakken bayani: 