10 men take 32 minutes to unload 15 containers. Given that all men work at the same rate, calculate how long it would take 15 men to unload 40 containers.
Here's what I did.
Let the number of men be m, time be t and containers be c.
m=kc/t (where k is an unknown constant)
Find k by substituting the rest of the values. However the answer I got differs from the answer which is 25.6mins. May I know whether my formula is wrong? Thanks.
10 men, 15 containers, 32 minutes
10 men, 30 containers, 64 minutes. (double the work, take double the time)
20 men, 30 containers, 32 minutes (double the workers, half the time)
impossible that 15 men, 40 container, can get 25.6 minutes?
M : T : C
10 : 32 : 15
(u can oni calculate 1 variable at a time)
if no. of men remain the same, the time taken for the men to unload the 40 containers would be longer.
40/15 = 2.2/3
32 x 2.2/3 = 85.1/3
M : T: C
10: 85.1/3 : 40
if men increase to 15, the time take for men to unload 40 containers would be shorter
15/10 = 1.1/2
85.1/3 divide 1.1/2 = 56.8/9 mins
My answer is 56.4 minutes. So there's nothing wrong with my formula?
Originally posted by bonkysleuth:10 men take 32 minutes to unload 15 containers. Given that all men work at the same rate, calculate how long it would take 15 men to unload 40 containers.
Here's what I did.
Let the number of men be m, time be t and containers be c.
m=kc/t (where k is an unknown constant)
Find k by substituting the rest of the values. However the answer I got differs from the answer which is 25.6mins. May I know whether my formula is wrong? Thanks.
It is correct. Your approach is the correct objective of the O level. Congratulations on understanding the direct and inverse relationship between variables.
i see nothing wrong with your formula, yup, it's correct