24. A bookshelf has n fiction books and six non-fiction books. If there are 150 ways to choose two books of each type, how many fiction books are on the bookshelf?

When you arrive at the lake, your friend realises he hasn’t got any swimming trunks. you need to ride to a sports shop. the sports shop is 8350 metres away. how many metres is it to cycle there and back?

Ametal rod is 2/5 meters long. it will be cut into pieces that are each 1/30 meters long. how many pieces will be made from the rod?

Evaluate 8j -k+148j−k+14 when j=0.25j=0.25 and k=1k=1.