Respuesta :
Answer:
40 min
Step-by-step explanation:
his sister can do it twice as fast so the boy does 1 and the sister does 2. he will do 1/3 of the work and it will take 1/3 of the time
Answer:
90 mins
Step-by-step explanation:
1 hour =60 mins
1/2 hour = 60/2=30
so, 60 +30=90