A bricklayer takes 3/8 of a minute to lay one brick. how many bricks will he lay in 2 hours?

If he takes 3/8 minute, he can do (3/8)(60) in 1 hour and double that amount in two hours... so...

Total : (3 bricks /8 minutes)(60 minutes/ 1hour)(2 hours) = (3/4)(60) = (3)(15) = 45 bricks