This chapter of the guide to Dragon Ball Z: Kakarot has a walkthrough for The Nutty Scientist side quest.
Time frame: From Android Terror Arrives - Episode 10: Intermission to Episode 10: Intermission
Reward: 168,013 EXP, 5x D Medal, Card 055, Fancy Necklace, Ultra Brain Bread
Where to start: East Ravine Area, as Gohan.
Bulma is waiting for you in the desert, near the mountains.
Receive the task and go to the places marked on the map. Talk to the man - he will point you to a place where you can find all three items.
Take the materials to the quest giver. This will complete the quest.