Change the sentences keeping the same meaning. 1. Joe collected his stamps in 3 years. It took.... 2. Joe is looking

1. Joe collected his stamps in 3 years. It took him 3 years to collect the stamps. 2. Joe is looking for some new stamps with his friend now. Joe and his friend are looking for some new stamps now. 3. Stamps with flowers cost less than the others. Stamps with flowers weren\'t more expensive than the others. 4. I want to do well on the test, so I can go to the University. If I want to do well on the test, I can go to the University. 5. It was a mistake not to study for the exam. Not studying for the exam was a mistake.