Workers in a coffee plantation take 18 days to pick coffee berries in 20% of the plantation. Class 8

Workers in a coffee plantation take 18 days to pick coffee berries in 20% of the plantation. Class 8

Question 1.

Workers in a coffee plantation take 18 days to pick coffee berries in 20% of the plantation. How many days will they take to complete the picking work for the entire plantation, assuming the rate of work stays the same? Why is this assumption necessary? Class 8

Solution:

For 20% work,

number of days taken = 18

So, for 1% work,

number of days required = [latex]\frac{18}{20}[/latex]

Therefore, for 100% work,

number of days required = [latex]\frac{18}{20}[/latex] × 100 = 90.

This assumption is necessary for applying unitary method.

Question 2.

The badminton coach has planned the training sessions such that the ratio of warm up : play : cool down is 10% : 80% : 10%. If he wants to conduct a training of 90 minutes. How long should each activity be done? Class 8

Solution:

Ratio of three activities

= 10% : 80% : 10% = 1 : 8 : 1.

Therefore, time for warm up

= [latex]\frac{90}{(1+8+1)}[/latex] × 1 = 9 minutes;

Time for play

= [latex]\frac{90}{(1+8+1)}[/latex] × 8 = 72 minutes;

and time for cool down

= [latex]\frac{90}{(1+8+1)}[/latex] × 1 = 9 minutes;