Basic Simplification Quiz Set 014

This is a multiplication by a power of 5. The best way is to observe that 25 = 5². There are 2 powers of 5. So append 2 zeroes and divide by 2², like this: $30400/4$ = 7600.

We have to find $38{3/16}$ - $16{3/38}$, which is same as ${611/16}$ - ${611/38}$ = 611 × ${38 - 16}/{38 × 16}$ = ${6721/304}$. So ${6721/304}$, which is same as: $22{33/304}$ is the required answer.

This is a multiplication by 9. Proceed like this: 277 × 9 = 277 × (10 - 1) = 277 × 10 - 277 = 2770 - 277 = 2493. Sometimes, the options can be ruled out by examining the units places, but for simpler cases these shortcuts will help you save time overall.

Let them have X and Y marbles, respectively. We have X - 2 = Y + 2, which gives X - Y = 4. By the second condition, X + 4 = 2(Y - 4), which can be re-arranged to X - 2Y = -12. Solving for Y, we get Y = 16.

We have to find $33{3/13}$ - $13{1/11}$, which is same as ${432/13}$ - ${144/11}$ = 432 × ${11 - 13}/{11 × 13}$ = ${2880/143}$. So ${2880/143}$, which is same as: $20{20/143}$ is the required answer.