question_answer 15)

Set up equations and solve them to find the unknown numbers in the following cases: (a) Add 4 to eight times a number; you get 60. (b) One-fifth of a number minus 4 gives 3. (c) If I take three-fourths of a number and add 3 to it, \[\text{I}\] get 21. (d) What \[\text{I}\] subtracted 11 from twice a number, the result was 15.                 (e) Munna subtracts thrice the number of notebooks he has from 50, he finds the result to be 8.                                                                        (f) Ibenhal thinks of a number. If she adds 19 to it and divides the sum by 5, she will get 8. (g) Anwar thinks of a number. If he takes away 7 from \[\frac{5}{2}\]of the number, the result is 23.                

Answer:

                (a) Let \['x'\] be the number. Then according to the question, we get \[4+8x=60\] \[\Rightarrow \]               \[8x=60-4\] \[\Rightarrow \]               \[x=\frac{56}{8}=7\] Therefore, the number is 7. (b) Let \['x'\] be the number. Then according to the question, we get \[\frac{1}{5}\times x-4=3\] \[\Rightarrow \]               \[\frac{x}{5}=3+4\] \[\Rightarrow \]               \[x=7\times 5=35\] Therefore, the number is 35. (c) Let \['x'\]be the number. Then according to the question, we get \[\frac{3x}{4}+3=21\] \[\Rightarrow \]               \[\frac{3x}{4}=21-3\] \[\Rightarrow \]               \[3x=18\times 4\] \[\Rightarrow \]               \[x=\frac{72}{3}=24\] Therefore, the number is 24. (d) Let \['x'\] be the number. \[2x-11=15\] \[\Rightarrow \]               \[2x=15+11\] \[\Rightarrow \]               \[x=\frac{26}{2}=13\] Therefore, the number is 13. (e) Let \['x'\] be the number The according to the question, we get \[50-3x=8\] \[\Rightarrow \]               \[3x=50-8\] \[\Rightarrow \]               \[x=\frac{42}{3}=14\] Therefore, the number is 14. (f) Let \['x'\] be the number, Then according to the question, we get \[\frac{x+19}{5}=8\] \[\Rightarrow \]               \[x+19=8\times 5\] \[\Rightarrow \]               \[x=40-19=21\] Therefore, the number is 21. (g) Let \['x'\] be the number Then according to the question, we get \[\frac{5}{2}x-7=23\] \[\Rightarrow \]               \[\frac{5}{2}x=23+7\] \[\Rightarrow \]               \[\frac{5}{2}x=30\] \[\Rightarrow \]               \[5x=60\] \[\Rightarrow \]               \[x=\frac{60}{5}=12\]