Maths 3 Mark Question

Total cost price = Price of pencils + Price of pens
= 30 + 90 + 25
= Rs. 145
Total amount sold = Price of pen + Price of pencils
= 20 + 70
= Rs. 90
Selling price – Cost price = 90 – 145 = -55
The negative sign implies loss
Hence, his net loss was Rs. 55.

x	-3	-2	-1	0	1	2	3
-3	+9	+6	+3	0	-3	-6	-9
-2	+6	+4	+2	0	-2	-4	-6
-1	+3	+2	+1	0	-1	-2	-3
0	0	0	0	0	0	0	0
1	-3	-2	-1	0	1	2	3
2	-6	-4	-2	0	2	4	6
3	-9	-6	-3	0	3	6	9

L.H.S.
(-13) × [(-6) + (-19)]
= (-13) × [-6 - 19]
= (-13) × (-25)
= 325
R.H.S.
(-13) × (-6) + (-13) × (-19)
= 78 + 247
= 325
L.H.S. = R.H.S. (Proved)

L.H.S.
18 × [9 + (-7)]
= 18 × 2
= 36
R.H.S.
18 × 9 + 18 × (-7)
= 162 + (-126)
= 36
So, L.H.S. = R.H.S. (Proved)

Let the distance covered in the direction of north be positive and that in the direction of south be negative.
Distance travelled to the north of Patna = 60km
Distance travelled to the south of Patna = -90km
Total distance travelled by the car = 60 + (-90)
= -30km
The car was 30km south of Patna.

Sum of 138 and -250:138 + (-250)
= 138 - 250
= -112
Sum of 136 and -272:
= 136 + (-272)
= 136 - 272
= -136
Subtracting the sum of -250 and 138 from the sum of 136 and -272:
-136 - (-112​)
= -136 + 112​
= -24