Question

Mark was given several thumbtacks. He gave 7 away to his best friend and then use one third of it to give to his mother. His mother got 5 thumbtacks. How many thumbtacks was Mark given? 2

Answer 1

Mark gave 7 TB to his best friend

1/3*(Total TB) to give his mother

His mother got 5

1/3*(Total TB) = 5

Total TB = 5*3

Total TB = 15 TB

now let's add those of your friend

Total = 15 + 7 = 22

Mark had 22 thumbtacks