These are the exercises from **Part 6 - [Accumulators](https://htdp.org/2019-02-24/part_six.html)**: - [ ] [`489`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/489.rkt) - [ ] [`490`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/490.rkt) - [ ] [`491`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/491.rkt) - [ ] [`492`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/492.rkt) - [ ] [`493`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/493.rkt) - [ ] [`494`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/494.rkt) - [ ] [`495`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/495.rkt) - [ ] [`496`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/496.rkt) - [ ] [`497`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/497.rkt) - [ ] [`498`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/498.rkt) - [ ] [`499`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/499.rkt) - [ ] [`500`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/500.rkt) - [ ] [`501`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/501.rkt) - [ ] [`502`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/502.rkt) - [ ] [`503`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/503.rkt) - [ ] [`504`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/504.rkt) - [ ] [`505`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/505.rkt) - [ ] [`506`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/506.rkt) - [ ] [`507`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/507.rkt) - [ ] [`508`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/508.rkt) - [ ] [`509`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/509.rkt) - [ ] [`510`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/510.rkt) - [ ] [`511`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/511.rkt) - [ ] [`512`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/512.rkt) - [ ] [`513`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/513.rkt) - [ ] [`514`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/514.rkt) - [ ] [`515`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/515.rkt) - [ ] [`516`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/516.rkt) - [ ] [`517`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/517.rkt) - [ ] [`518`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/518.rkt) - [ ] [`519`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/519.rkt) - [ ] [`520`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/520.rkt) - [ ] [`521`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/521.rkt) - [ ] [`522`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/522.rkt) - [ ] [`523`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/523.rkt) - [ ] [`524`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/524.rkt) - [ ] [`525`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/525.rkt) - [ ] [`526`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/526.rkt) - [ ] [`527`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/527.rkt) - [ ] [`528`](https://github.com/how-to-design-programs/how-to-design-programs-solutions/blob/master/src/528.rkt)