Question

Manju, who works at Ganesh Fruit juice center, prepares 51 glasses of milkshake in 4 min, 18 sec in his first shift. After having a sandwich, he prepares 73 glasses in 7 min 13 sec. After another sandwich, he prepares 112 glasses in 12 min, 24 sec. The container in which the milkshake is prepared contains a maximum of 9 glasses of a drink at a time. The approximate average time (to the nearest integer) of preparation of one container of the drink, if he starts with a fresh container each time is (in seconds) ___

Answer 1

In the first shift, he uses the container 6 times.
(45 glasses in 5 rounds and the remaining 6 glasses in the $6^{th}$ round. Similarly, he prepared 73 glasses in 9 rounds, and 112 glasses in 13 rounds.)
Hence, the required average
= $\frac{totaltime}{totalnumberofrounds}$
= (4 min 18 s + 7 min 13 s + 12 min 24 s)/ (6 + 9 +13)
= (23 min+55s)/ 28 = 51 seconds (rounded)