How smart are you? – Get involved!!!

Let’s see how many of you can solve the following riddle! – Let us know the answers via twitter!!! @Grimedaily

You see a shirt for £97, but You don’t have the money, so you borrow £50 off you’re Mum and £50 of you’re Dad. £50+£50=£100, right? … You buy the shirt and have £3 change, you give £1 to you’re Mum, £1 to you’re dad and you keep £1 to yourself.
Now you owe them both £49.

£49+£49=£98 + YOUR £1 = £99

Where has the other pound gone?