15 pipes, each having the same diameter, can fill a cistern in 12 minutes. How long will it take for 6 pipes, each with double the original diameter, to fill the same cistern at the same speed of the flow?
A boat at anchor is rocked by waves whose consecutive crests are 100 m apart. The wave velocity of the moving crests is 25 ms⁻¹. What is the frequency of rocking of the boat?
4 workers working 6 hours per day can finish painting a wall in 21 days. If 7 workers work for 4 hours per day, in how many days will they be able to finish the same work?
If in a certain code language, PUZZLING is written as ZZPUGNIL and JIPIJAPA is written as IPIJAPAJ, then what will SWIZZLED be written as in the same code?
