In three more years miguel's grandfather will be six times as old as miguel was last year. when miguel's grandfather present age is added to his grandfathers age is added to his grandfathers present age the total is 68. how old is his grandfather now ?

"In three more years,Miguel's grandfather will be six times as old as Miguel was last year. When Miguel's present age is added to his grandfather's present age, the total is 68. How old is each one now?"

Miguel is 11 years old and his grandfather is 57 years old.
Last year Miguel was 10. In three more years his grandfather would be 60. 60/6=10. 11+57=68

C. i believe it is (5×(-20))+(100×(0.7))