The flexural strength of concrete for M25 grade concrete as per IS 456:2000 is calculated using the formula 0.7√fck. What is its value?

A concrete slab measuring 4 m × 4 m × 0.125 m is to be compacted using a needle vibrator. If the effective compaction radius of the needle is r = 0.3 m, and the area covered per insertion in a square grid arrangement corresponds to an effective spacing of r√2, what is the minimum number of insertions required to cover the slab area?

A total volume of 5 m3 of concrete was produced using 32 bags of cement (standard 50 kg bag). Calculate the cement content of the mix in kg/m3.