A car runs 16 km using 1 litre of petrol. How far will it go using 2 3/4 litres of petrol. Class 7

A car runs 16 km using 1 litre of petrol. How far will it go using 2 3/4 litres of petrol. Class 7

Question 1.

A car runs 16 km using 1 litre of petrol. How far will it go using 2[latex]\frac {3}{4}[/latex] litres of petrol? Class 7

Solution:

In 1 litre, distance covered = 16 km.

So, in 2[latex]\frac {3}{4}[/latex] litre, distance covered

= 16 × 2[latex]\frac {3}{4}[/latex] km 22 km

= 16 × [latex]\frac {11}{4}[/latex] km = 4 × 11 km = 44 km.

Question 2.

Amritpal decides on a destination for his vacation. If he takes a train, it will take him 5[latex]\frac {1}{6}[/latex] hours to get there. If he takes a plane, it will take him [latex]\frac {1}{2}[/latex] hour. How many hours does the plane save? Class 7

Solution:

Plane will save = (5[latex]\frac {1}{6}[/latex] - [latex]\frac {1}{2}[/latex]) hours

= ([latex]\frac {31}{6}[/latex] - [latex]\frac {1}{2}[/latex]) = ([latex]\frac {31}{6}[/latex] - [latex]\frac{1 \times 3}{2 \times 3}[/latex])

= ([latex]\frac {31}{6}[/latex] - [latex]\frac {3}{6}[/latex]) = [latex]\frac {28}{6}[/latex] hours = 4[latex]\frac {2}{3}[/latex] hours.

Question 3.

Mariam's grandmother baked a cake. Mariam and her cousins finished [latex]\frac {4}{5}[/latex] of the cake. The remaining cake was shared equally by Mariam's three friends. How much of the cake did each friend get? Class 7

Solution:

Cake finished by Mariam and her cousins = [latex]\frac {4}{5}[/latex]

So, remaining cake = 1 - [latex]\frac {4}{5}[/latex] = [latex]\frac {1}{5}[/latex]

Thus, cake shared by each friend

= [latex]\frac {1}{5}[/latex] ÷ 3 = [latex]\frac {1}{5}[/latex] × [latex]\frac {1}{3}[/latex] = [latex]\frac {1}{15}[/latex]